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• PdPtV nanoparticles (NPs) are synthesized using the oil-phase co-reduction strategy. • The PdPtV/CeO 2 −ZrO 2 catalyst performs the best in ethylbenzene (EB) oxidation. • PdPtV/CeO 2 −ZrO 2 shows large EB adsorption capacity, good reducibility, and strong surface acidity. • TPD and in situ DRIFTS are used to study the reversible poisoning of PdPtV/CeO 2 −ZrO 2 by SO 2. • V doping to PdPt NPs protects the active PdPt sites from being poisoned by SO 2. The PdPtVO x /CeO 2 −ZrO 2 (PdPtVO x /CZO) catalysts were obtained by using different approaches, and their physical and chemical properties were determined by various techniques. Catalytic activities of these materials in the presence of H 2 O or SO 2 were evaluated for the oxidation of ethylbenzene (EB). The PdPtVO x /CZO sample exhibited high catalytic activity, good hydrothermal stability, and reversible sulfur dioxide-poisoning performance, over which the specific reaction rate at 160°C, turnover frequency at 160°C (TOF Pd or Pt), and apparent activation energy were 72.6 mmol/(g Pt ⋅sec) or 124.2 mmol/(g Pd ⋅sec), 14.2 sec−1 (TOF Pt) or 13.1 sec−1 (TOF Pd), and 58 kJ/mol, respectively. The large EB adsorption capacity, good reducibility, and strong acidity contributed to the good catalytic performance of PdPtVO x /CZO. Catalytic activity of PdPtVO x /CZO decreased when 50 ppm SO 2 or (1.0 vol.% H 2 O + 50 ppm SO 2) was added to the feedstock, but was gradually restored to its initial level after the SO 2 was cut off. The good reversible sulfur dioxide-resistant performance of PdPtVO x /CZO was associated with the facts: (i) the introduction of SO 2 leads to an increase in surface acidity; (ii) V can adsorb and activate SO 2 , thus accelerating formation of the SO x 2− (x = 3 or 4) species at the V and CZO sites, weakening the adsorption of sulfur species at the PdPt active sites, and hence protecting the PdPt active sites to be not poisoned by SO 2. EB oxidation over PdPtVO x /CZO might take place via the route of EB → styrene → phenyl methyl ketone → benzaldehyde → benzoic acid → maleic anhydride → CO 2 and H 2 O. [Display omitted] [ABSTRACT FROM AUTHOR]

In ethylbenzene dehydrogenation process, the produced coke is the main source of catalyst deactivation, deterioration of stainless steel piping (carburization) and the flow pass plugging. The novelty of this work is determination, ranking and modeling of influencing factors and their interactions on the rate of coke formation in ethylbenzene dehydrogenation process including independent parameters such as styrene and toluene concentrations, surface temperature, the reactor shape factor and steam to ethylbenzene (St/EB) weight ratio. A laboratory setup was used to investigate the effect of above listed parameters and the response surface methodology (RSM) was used to analyze the experiments and optimize the parameters. The ANOVA results illustrated that the model is significant and able to predict coke. The p-values for all parameters are less than 0.05, indicating these parameters are effective factors on coke formation. The results revealed that by increasing styrene and toluene concentrations and surface temperature, the rate of coke formation increases. In such circumstances, surface temperature showed maximum effect due to the increase of cracking reactions and the production of coke precursors such as stilbene, anthracene etc. On the other hand, the effect of St/EB weight ratio on the rate of coke formation is inverse. The results obtained from SEM/EDS analysis showed the filamentous coke forms on the surface of 304 H austenitic steel. [Display omitted] • Styrene and toluene concentrations, surface temperature, shape factor and St/EB ratio were identified as influencing factors on coke formation. • RSM method was used to analyze and optimize the independent parameters on coke formation. • GC and GC-MS were performed to confirm the presence of coke precursors. • EDX spectra revealed the formation of filamentous coke on the surface of austenitic steel. [ABSTRACT FROM AUTHOR]

The typical conventional plantwide control structure sets the flow rate of the fresh feed entering the process. Sometimes marketing or safety requirements dictate that the flowrate of the product leaving the process must be flow controlled. This structure is called "on-demand." Important examples of chemicals that must be supplied on an "as-needed" basis include hydrogen, oxygen, synthesis gas, toxic hydrogen cyanide and explosive nitrotoluene. Since the output flow is fixed in an on-demand control structure, the material balance loops controlling liquid levels and gas pressures must work their way back upstream through the process to eventually adjust the fresh feed streams. A novel on-demand control structure is developed in this paper that reduces peak dynamic disturbances throughout the process by immediately changing upstream flow rates in a "feed-backward" manner when the product flow rate is changed. ● A new on-demand control structure is proposed and its performance evaluated for throughput and feed composition disturbances. ● The numerical example is the ethyl benzene process that features two reactors, two distillation columns and two liquid recycle streams. ● Comparisons are made of a conventional plantwide control structure with several on-demand control structures. [ABSTRACT FROM AUTHOR]

Landfill gas emissions cause serious environmental concerns due to the presence of methane (CH 4), an important greenhouse gas (GHG) and several harmful volatile organic compounds (VOCs) such as xylene (X) and ethylbenzene (EB). A series of 9 up-flow biofilters (3 sections of 0.3 m each) packed with inorganic materials were used to eliminate CH 4 as a single pollutant, a binary mixture of X and EB and a ternary mixture of CH 4 , X and EB. The CH 4 concentration range was 2000–10000 ppmv while the VOCs (X and EB) individual concentrations were 200, 400 and 600 ppmv for empty bed residence times (EBRTs) ranging from 2.25 to 9 min over a period of 242 days. The highest CH 4 removal efficiency (RE) in the ternary mixture was 41 ± 3% at a CH 4 concentration of 2000 ppmv and X and EB individual concentrations of 200 ppmv for an EBRT of 9 min. Meanwhile, the highest X and EB-REs of 58 ± 3 and 57 ± 3% were obtained respectively, at the same concentrations of the components but at a shorter EBRT of 4.5 min. Almost 40% of CH 4 biodegradation took place on the top section of the bioreactor while 50–60% of the VOCs biodegradation occurred in the middle section. [ABSTRACT FROM AUTHOR]

• Cu-NP dispersed on diverse inorganic supports via micelle technique. • CuO/Al 2 O 3 nanoparticles exhibit irregular or 20–40 nm-long rod-like shapes. • 15 % CuO/Al 2 O 3 nanocomposites exhibited superior EB conversion and AP selectivity. • Promising catalyst for high selectivity and consistent ethylbenzene conversion. Copper-based (Cu-NP) uniformly dispersed on various inorganic supports (alumina, silica, titania, and zirconia) were prepared by the reverse microemulsion technique. These nanoparticles were used for the selective oxidation of ethylbenzene (EB) to produce acetophenone (AP) as the main product in the presence of Tert‑butyl hydroperoxide(TBHP) as an oxidant. This study focused on creating Cu-nanoparticles evenly dispersed on alumina using varying Cu-loadings (5 %, 10 %, and 15% wt.) and Brij-35 as the surfactant. The resulting catalytic material was characterized using various physicochemical techniques like XRD, FESEM, HRTEM, XPS and physisorption techniques. Various parametric studies were conducted, such as the effects of temperature, catalyst support, catalyst loading, and TBHP loading to optimize the EB conversions and AP selectivity. Among the various catalyst loadings, 15 % CuO/Al 2 O 3 (15 % of the copper content) nanocomposites showed exceptional performance, with the highest EB conversion rate (99.7 %) and AP selectivity (98.5 %) compared to other nanocomposites. The catalyst's stability and recyclability over four cycles were attributed to the strong copper oxide-alumina interaction. These findings suggest that this nanocomposite material is a promising candidate for catalytic applications, offering high selectivity and consistent EB conversion rates. [Display omitted] [ABSTRACT FROM AUTHOR]

[Display omitted] • ZnO@polyaniline/coal was synthesized as enhanced for photocatalyst for CR dye. • It is achieved 100 % removal (40 min) and mineralization (100 min) for 5 mg/L. • The synergetic effect validate enhancement in the activity after the integration. • The oxidation pathway involves decarboxylation and de-hydroxylation reactions. • The ecotoxicity studies demonstrate safe end products after the treatment steps. ZnO@polyaniline/coal nanocomposite (ZnO@PANI/C) was synthesized and characterized by different analytical techniques as potential enhanced photocatalyst for the successful oxidation of Congo red dye (CR) into eco-friendly end-products. The investigated CR concentration (5 mg/L) was completely decolorized after 120 min, 100 min, 80 min, and 40 min after the incorporation of ZnO@PANI/C dosages at 0.2 g/L, 0.3 g/L, 0.4 g/L, and 0.5 g/L, respectively. The synergetic studies demonstrate a significant impact of the integrated components (coal, polyaniline (14.2 % oxidation of CR), ZnO (21.6 % oxidation of CR), 43.7 % (PANI/C oxidation of CR), and 64.3 % (ZnO/C oxidation of CR)) on the catalytic activity of ZnO@PANI/C (100 % oxidation of CR), which is higher than that of the individual components. The investigation of TOC content reflects that the complete mineralization can be detected after 100 min and validates the formation of different species of intermediates started by sodium-3-(phenyl diazenyl) naphthalene-1-sulfonate until detecting ethyl benzene. The findings of the oxidizing trapping tests demonstrate the controlling impact of the hydroxyl radicals as the oxidation in the presence of its trapping reagent (Isopropanol) declined to 8.6 %. The oxidation pathway of CR over ZnO@PANI/C involved a progressive series of decarboxylation and dihydroxylation ended by ethylbenzene, which in turn produced nontoxic products such as H 2 O and CO 2. The eco-toxicity tests reflect the efficiency of the photo-oxidation of CR contaminants by ZnO@PANI/C in reducing acute toxicity (LC50 and EC50 > 100) and chronic (ChV > 10) toxicities of CR dye after 60 min of remediation. [ABSTRACT FROM AUTHOR]

Efficient catalytic cleavage of C–O bonds in lignin derivatives is crucial for converting these compounds into valuable chemicals. The reliance on expensive noble metals and harsh operational conditions poses significant challenges for existing catalyst systems. In response, we have developed a Ni-based catalyst through an acetone-driven etching-deposition-pyrolysis technique, tailored to maximize exposure of Ni active sites. Systematic optimization of the support's surface properties, pyrolysis temperature, and Ni loading were instrumental in augmenting C–O bond cleavage efficiency in aromatic ethers. Remarkably, the catalyst, 2Ni/CNS-500, facilitated the cleavage of the C–O bond in diphenyl ether (DPE) to monomers under mild conditions (140 °C for 2 h under 1 MPa H 2 pressure), surpassing the performance of several existing heterogeneous Ni-based catalysts. The catalyst's superior performance is attributed to the robust interaction between nickel and carbon nanosphere (CNS) species and the significant exposure of nickel active sites. Versatility was demonstrated with a variety of lignin-derived substrates, including 4-phenoxy phenol (4- O -5), benzyl phenyl ether (α- O -4), phenyl ethyl benzene (β- O -4), and anisole, showcasing the catalyst's broad applicability. Therefore, the acetone-driven etching-deposition-pyrolysis strategy is considered a promising method for preparing highly dispersed nickel-based hydrogenolysis of lignin derivatives catalysts with broad industrial application prospects. [Display omitted] • 2Ni/CNS-500 was prepared through an etching-deposition-pyrolysis technique. • Acetone exhibited positive effects on dispersing the Ni nanoparticles on the phenolic resin carbon nanosphere. • The dimensions of Ni nanoparticles were governed by preparation conditions. • Selective hydrogenolysis of diphenyl ethers was achieved under mild conditions. • 2Ni/CNS-500 catalyst exhibits good recovery and recyclability. [ABSTRACT FROM AUTHOR]

[Display omitted] • Ethylbenzene is synthesized by alkylation of benzene using CO 2. • A Single-bed catalyst system for forming ethylbenzene is constructed. • Effect of Brønsted Acid Density and Intragranular Diffusion of HZSM-5 on Product Distribution. • Reaction networks were extensively explored using GC–MS and various model reactions. The selective synthesis of specific value-added aromatic hydrocarbons through CO 2 hydrogenation holds significant strategic importance in mitigating energy and climate issues. However, the process of forming ethylated side chains on benzene rings is challenging, and the methods reported are often limited by multi-bed systems. Here, we show the first CO 2 hydrogenation in tandem coupling with benzene alkylation to synthesize ethylbenzene over a single-bed system containing ZnFeO x and nano ZSM-5 catalysts. The results indicated that the bifunctional catalyst composed of ZnFeO x with a Zn/Fe ratio of 0.5 and nano-HZSM-5 exhibits excellent catalytic performance under optimized conditions. The benzene conversion reaches 28.0 %, ethylbenzene selectivity is 61.3 % and the conversion of CO 2 is remarkably high, achieving 45.0 %. This single-bed system significantly promotes the in-situ utilization of ethylation intermediates. The introduction of zinc promoted the formation of ZnFe 2 O 4 spinel, which increased the number of active sites due to its superior dispersibility and reducibility. Nano-HZSM-5 demonstrated outstanding ethylbenzene selectivity and catalytic stability owing to its unique shape selectivity, moderate acidity, and superior diffusion properties. This study further explores the reaction network and mechanism through GC–MS analysis and various model reactions, elucidating the formation pathways of primary products in detail. This research provides a new strategy for the controllable synthesis of ethylbenzene using CO 2 as a C 1 source in a single-bed system. [ABSTRACT FROM AUTHOR]

• Rational functions were trained as VLE surrogate models with thermodynamic consistency. • Superstructure-based extractive distillation process synthesis was solved within a few seconds. • A multi-level solvent screening was performed for ethylbenzene/styrene separation. • C 2 H 2 Br 4 was found to reduce cost by 27.9 % compared to the benchmark sulfolane. When designing extractive distillation processes, using selectivity and capacity at infinite dilution alone is hard to identify the real optimal solvent with minimal process cost. To overcome this problem, a new process-driven solvent screening approach is developed. As simple and reliable surrogate models, rational functions (algebraic fractions such that the numerator and the denominator are polynomials) and multivariate polynomials (a subset of rational functions) are trained to interpolate vapor–liquid equilibria with thermodynamic consistency. The surrogate models can directly be embedded into superstructure-based extractive distillation process design to obtain optimal solutions within a few seconds. This enables to evaluate the real process performance of numerous solvents efficiently. Incorporating the accelerated process design strategy, a multi-level solvent screening framework is proposed and exemplified for the separation of a close-boiling mixture ethylbenzene/styrene. The solvent C 2 H 2 Br 4 ultimately enables a cost reduction of 27.9 % compared to the industrially used benchmark solvent sulfolane. [ABSTRACT FROM AUTHOR]

[Display omitted] • The constructed synthetic bacterial consortium effectively degraded aromatic VOCs. • Degradation mechanism elucidated through gene-protein-metabolite interactions. • Identified metabolic pathways for benzene, toluene, and ethyl benzene. Aromatic volatile organic compounds (VOCs) are prevalent pollutants in chemically contaminated sites, posing threats to ecological safety and human health. To address the challenge of achieving low-carbon, low-cost, green, and sustainable in-situ remediation at these sites, a highly efficient synthetic bacterial consortium was constructed for biodegradation of selected pollutants (i.e., benzene, toluene, ethyl benzene, m-xylene, chlorobenzene, p-chlorotoluene, and p-chlorotrifluorotoluene). Under optimized conditions, the consortium achieved a total degradation efficiency of 77%. Biodegradation of benzene, toluene, ethyl benzene, and m-xylene followed first-order kinetics, while p-chlorotoluene and p-chlorotrifluorotoluene followed zero-order kinetics. The mechanisms were analyzed using microbiome technology at genetic, protein, and metabolic levels, identifying key enzymes and differences in protein expression and related metabolites. Carbon dioxide measurements and fluorescence spectrum analysis elucidated the transformation pathways. These findings underscore the consortium's significant potential for achieving effective, eco-friendly, and sustainable bioremediation of aromatic VOCs in chemically contaminated environments. [ABSTRACT FROM AUTHOR]

The development of catalysts and processes with high activity, good selectivity and easy reproducibility and regeneration is the core of the solution for the oxidation of ethylbenzene to acetophenone. In this paper, the catalyst of cobalt metal oxide supported on TS-1 zeolite co-modified by alkali treatment and titanium silicon composite oxide was prepared. The catalysts were characterized by XRD, Raman, N 2 adsorption-desorption, SEM, TEM, XPS, FT-IR and UV–vis techniques to establish the correlation between physical and chemical properties and catalytic performance. Among the prepared catalysts, SiO 2 and TiO 2 co-coated TS-1 supported 3.75 wt % Co 3 O 4 catalyst showed better oxidation activity. Under the optimized reaction conditions: T = 80 °C, t = 8 h, m cat = 0.03 g, n EB: n HAC: n KBr: n H 2 O 2 = 1 : 21: 0.1 : 16, the conversion of ethylbenzene was as high as 86.7 % and the selectivity of acetophenone was 85.6 %. After repeated tests, it showed good cycle and regeneration reaction performance. The high activity of this catalyst is attributed to the synergistic effect of cobalt oxide and TS-1 zeolite, and the mesoporous structure of titanium-silicon composite oxide is conducive to the adsorption and diffusion of reactants, intermediates and products. The Co 3 O 4 /HTS-1@T + S catalyst shows good oxidation activity in the catalytic oxidation of acetophenone by ethylbenzene. [Display omitted] • The combined modified TS-1 micro-mesoporous coexistence. • The Co 3 O 4 /HTS-1@T + S catalyst has the best catalytic activity for ethylbenzene oxidation. • The reaction is a free radical and acid reaction mechanism. [ABSTRACT FROM AUTHOR]

Carbon-based materials have stood out due to their variety of applications such as photocatalysis. Thus, strontium hexaferrite dispersed in silica was prepared by the Pechini method and used as a catalyst in the ethylbenzene reaction to produce carbon filaments and subsequent application in the photodegradation of the remazol red dye. The presence of SrFe 12 O 19 , α-Fe 2 O 3 and amorphous silica phases was confirmed in the XRD (X-ray diffraction), Raman and XPS (X-ray photoelectron spectroscopy) analysis. The SEM (scanning electron microscopy) and TEM (transmission electron microscopy) results of the fresh oxides indicate cluster and sponge-like morphology. The formation of carbon filaments was observed by SEM analysis as a result of catalytic chemical vapor deposition (CCVD) of ethylbenzene. TEM images confirm the generation of multi-walled carbon nanotubes with an average diameter of 27.9 nm. Besides the presence of the SrFe 12 O 19 and SiO 2 phases, the diffractograms of the samples after the reaction shows the formation of graphite carbon and Fe0, confirming the reduction of α-Fe 2 O 3 which was also verified in the TPR-H 2 profile. The growth of nanotubes occurs from metallic iron, considering that the tip of the tube contains only iron, according to EDS (energy-dispersive X-ray spectroscopy) results. The Raman spectrum exhibited the characteristic D and G bands of carbon, where the I D /I G ratio decreased with increasing temperature. The reaction with the best catalytic performance achieved an average ethylbenzene conversion of 99 % and was more selective to ethene (∼93 %) at 650 °C. Furthermore, it was possible to carry out a simple theoretical-computational study regarding the distribution of the sites in a 2D plane by constructing maps and proposing a mechanism for the formation of carbon nanotubes from the ethylbenzene conversion. Finally, the obtained materials were applied in the remazol red dye degradation, achieving complete degradation in 15 min for the material synthesized at 650 °C. [Display omitted] • Carbon nanotubes were obtained by ethylbenzene conversion over SrFe 12 O 19 /SiO 2. • The nanotube formation was favored with increasing temperature. • The tip of the tube containing Fe0 followed the nanotubes growth. • SrFe 12 O 19 /SiO 2 650 °C exhibited ∼100 % degradation in 15 min for remazol red dye. [ABSTRACT FROM AUTHOR]

[Display omitted] • ZSM-12 with various morphologies and acidity were synthesized. • Acid distribution of ZSM-12 is crucial to the alkylation performance. • More Brønsted acid sites in channel are beneficial to the high selectivity to p -TBEB. Para - tert -butyl ethylbenzene (p -TBEB) is an important polymer monomer raw material to produce poly (tert -butylstyrene). Achieving relatively high selectivity to p -TBEB (S p -TBEB) by shape selective alkylation of ethylbenzene with isobutylene is highly attractive, and it is crucial to clarify the major factors affecting S p -TBEB. Herein, ZSM-12 zeolites with various morphology or acid distribution were synthesized by altering alkalinity or structure directing agent (SDA). Despite different morphology of MTW(70)-M- x series samples using MTEACl as the SDA, they show similar catalytic performance in alkylation of ethylbenzene with isobutylene due to their similar acid distribution. On the other hand, MTW(1 0 0)-M-0.06 and MTW(1 0 0)-T with various morphology, synthesized with MTEACl and TEAOH as the SDA, respectively, exhibit quite different selectivity to the target product in this reaction. MTW(1 0 0)-M-0.06 has much higher S TBEB (87 % vs. 70 %) and S p -TBEB (95 % vs. < 60 %) than MTW(1 0 0)-T, which is attributed to that MTW(1 0 0)-M-0.06 possesses much more Brønsted acid sites distributed in the micropore channel. This provides a route to improve the selectivity to main product (TBEB, especially p -TBEB) of alkylation of ethylbenzene with isobutylene over ZSM-12 zeolite even other zeolites. [ABSTRACT FROM AUTHOR]

Methyl salicylate (MeSa) is known as a volatile plant pathogen biomarker and a chemical warfare agent simulant. Herein, high performance MeSa gas sensors were developed by optimizing morphology and composition of noble metal decorated tungsten trioxide (WO 3) nanofibers. Using optimized nanofibers, 100 ppb of MeSa were readily sensed in dry air whereas the calculated low limit of detection (LLOD) is expected to be in a few tens of ppb. Pt-WO 3 (1.1 at% Pt) nanofibers also show an excellent selectivity over other volatile organic compounds including aromatic compounds (i.e., benzene, toluene, ethyl benzene, p-xylene). Systematic characterization of sensors in environments with different oxygen contents indicated that surface carrier concentration significantly altered as a function of Au and Pt content. Although 1.7 at% Au-WO 3 nanofibers based sensor has higher sensing response toward MeSa, 1.1 at% Pt-WO 3 nanofibers were found to be a more promising sensing material for MeSa detection because of higher selectivity over other VOCs and lower calculated LLOD (∼41 ppb). • Pt and Au doped WO 3 nanofibers showed excellent sensing performance toward MeSa. • Low detection limit of 100 ppb was experimentally demonstrated. • Pt-WO 3 nanofibers have good selectivity toward MeSa over BTEX and other VOCs. • Sensing response toward MeSa can be altered by modulating energy barrier through Au and Pt dopant concentration. [ABSTRACT FROM AUTHOR]

Aromatic hydrocarbons like benzene, toluene, xylene, and ethylbenzene (BTEX) can escape into the environment from oil and gas operations and manufacturing industries posing significant health risks to humans and wildlife. Unlike conventional clean-up methods used, biological approaches such as bioremediation can provide a more energy and labour-efficient and environmentally friendly option for sensitive areas such as nature reserves and cities, protecting biodiversity and public health. BTEX contamination is often concentrated in the subsurface of these locations where oxygen is rapidly depleted, and biodegradation relies on anaerobic processes. Thus, it is critical to understand the anaerobic biodegradation characteristics as it has not been explored to a major extent. This review presents novel insights into the degradation mechanisms under anaerobic conditions and presents a detailed description and interconnection between them. BTEX degradation can follow four activation mechanisms: hydroxylation, carboxylation, methylation, and fumarate addition. Hydroxylation is one of the mechanisms that explains the transformation of benzene into phenol, toluene into benzyl alcohol or p-cresol, and ethylbenzene into 1-phenylethanol. Carboxylation to benzoate is thought to be the primary mechanism of degradation for benzene. Despite being poorly understood, benzene methylation has been also reported. Moreover, fumarate addition is the most widely reported mechanism, present in toluene, ethylbenzene, and xylene degradation. Further research efforts are required to better elucidate new and current alternative catabolic pathways. Likewise, a comprehensive analysis of the enzymes involved as well as the development of advance tools such as omic tools can reveal bottlenecks degradation steps and create more effective on-site strategies to address BTEX pollution. [Display omitted] • Fumarate addition is an alternative activation step in Ethylbenzene biodegradation. • Benzyl alcohol and cresol are two alternative intermediates in Toluene's pathway. • Omics tools can help to identifty bottleneck steps and unknown compounds. • Benzene methylation and hydroxylation are simultaneously activated mechanism. [ABSTRACT FROM AUTHOR]

[Display omitted] • MXenes were synthesized from safer starting materials and at lower temperatures than previously used. • MAX phases from activated carbon (AC) and graphite were mostly similar, but the former displayed higher surface area. • Large microporous surface area in AC-based MXene showed superior BTEX sorption. • AC-based MXene demonstrated efficient regenerative potentials over several cycles unlike graphite variant. • Selection of base carbon for MXene should be according to the intended application. MXenes, a group of emerging 2D metal carbides with unique properties and expanding potential applications, have attracted researchers' interests. However, high synthesis costs and safety concerns have imposed limitations on their research and development. Here, we report a low-cost and safer synthesis method for a titanium-MXene, which we then test for its efficacy as an adsorbent for organics contamination in water. For the synthesis, we examine how different carbon forms (graphite and activated charcoal (AC)) impact the MXene properties and application. Instead of expensive and high-risk pure titanium as a precursor, cheap and easy-to-handle titanium oxide was used, while achieving lower-temperature synthesis through the molten-salt shielded synthesis approach. The resulting 3D MAX phases were separately etched into 2D-MXenes and characterized extensively. The synthesised MXenes were tested as adsorbents in adsorption experiments under various conditions. The data obtained were fitted to isotherm and kinetic models to understand the adsorption mechanisms. Although the AC-based MXene exhibited a much larger BET surface area compared to the graphite-based MXene (24 m2/g vs 2 m2/g respectively), other characterization results indicated that both materials had remarkably similar morphological and functional properties. Additionally, both MXenes effectively removed at least 80 % of the initial contaminant concentration. However, AC-based MXene is cheaper to produce and demonstrated superior regenerative capabilities over three cycles of regeneration and reuse. Also, its reuse potential is less affected by oxidation during the regeneration process. This study concludes that MXenes can be synthesized at a lower cost and highlights the crucial role of the carbon form used in synthesis for the MXene subsequent application. Specifically, AC-based MXenes show great potential for clean water recovery applications and could be a good candidate for analytical chemistry purposes. [ABSTRACT FROM AUTHOR]

[Display omitted] • Chemical recycling of polystyrene using technology ready yields > 99 % pure styrene. • The process is thermodynamically (<10 MJ/kg) and economically competitive. • 60% of virgin polystyrene can be replaced by chemical recycling. Less than 5% of polystyrene is recycled, motivating a search for energy efficient and economical methods for polystyrene recycling that can be deployed at scale. One option is chemical recycling, consisting of thermal depolymerization and purification to produce monomer-grade styrene (>99%) and other co-products. Thermal depolymerization and distillation are readily scalable, well-established technologies; however, to be considered practical, they must be thermodynamically efficient, economically feasible, and environmentally responsible. Accordingly, mass and energy balances of a pyrolysis reactor for thermal depolymerization and two distillation columns to separate styrene from α-methyl styrene, styrene dimer, toluene, and ethyl benzene co-products, were simulated using ASPEN to evaluate thermodynamic and economic feasibility. These simulations indicate that monomer-grade styrene can be recovered with energy inputs <10MJ/kg, comparable to the energy content of pyrolysis co-products. Thermodynamic sensitivity analysis indicates the scope to reduce these values and enhance the robustness of the predictions. A probabilistic economic analysis of multiple scenarios combined with detailed sensitivity analysis indicates that the cost for recycled styrene is approximately twice the historical market value of fossil-derived styrene when styrene costs are fixed at 15% of the total product cost or less than the historical value when feedstock costs are assumed to be zero. A Monte Carlo and Net Present Value-based economic performance analysis indicates that chemical recycling is economically viable for scenarios assuming realistic feedstock costs. Furthermore, the CO 2 abatement cost is roughly $1.5 per ton of averted CO 2 , relative to a pyrolysis process system to produce fuels. As much as 60% of all polystyrene used today could be replaced by chemically recycled styrene, thus quantifying the potential benefits of this readily scalable approach. [ABSTRACT FROM AUTHOR]

The synthesis of value-added aromatic products, such as para-ethyl-toluene (PetT), from the greenhouse gas carbon dioxide (CO 2) and renewable hydrogen (H 2) is greatly desired. However, considerable challenges arise due to complex kinetics and difficulties in arranging multiple active components. Herein, we present a strategy for the selective synthesis of PetT via CO 2 hydrogenation in the presence of ethylbenzene via tandem reactions over a composite catalyst comprising Zn-Zr binary oxide and a modified crystal-stacking HZSM-5 zeolite, achieving over 70% PetT selectivity in the ethyl-toluene (ET) isomers (∼80% in the C 5+ hydrocarbons). State-of-the-art (quasi) in situ characterizations and corresponding theoretical calculations confirmed the designed reaction route involving stepwise activation of CO 2 to methoxy species and enhanced aromatic cycles for the formation of C–C bonds. And precisely controlled transfer and transformation of intermediate methoxy species contribute to the promoted performance in the selective synthesis of PetT. [Display omitted] • 80% ET containing 70% PetT was obtained over an oxide-zeolite composite catalyst. • Stepwise CO 2 activation and enhanced aromatic cycle afforded the tandem reactions. • Methoxy transferring makes great effect on the efficiency of tandem processes. • Key role of surface methoxy species is unveiled by experimental and DFT results. • Increasing components intimacy and zeolite acidity help increase performance. [ABSTRACT FROM AUTHOR]

• The FeAl40 catalyst has higher initial activity of ethylbenzene dehydrogenation. • A suitable abrasion-resistant property can be obtained over the FeAl40 catalyst. • The adding alumina inhibits the formation of KFe 11 O 17. • The FeAl40 catalyst has great potential for industrial application in CFB unit. In the traditional ethylbenzene dehydrogenation process, much superheated steam is needed to ensure the activity and stability of the catalyst, inevitably leading to high energy consumption. A novel ethylbenzene dehydrogenation process based on a circulating fluidized bed (CFB) reactor was used for the ethylbenzene dehydrogenation reaction under a low steam-to-oil ratio. In this work, a series of Fe-Al-based catalysts were prepared by a sol-gel method and the effect of alumina content on the catalytic performance of Fe-Al-based catalyst for ethylbenzene dehydrogenation was investigated. Among a series of Fe-Al-based catalysts, the FeAl40 catalyst (the Fe-Al-based catalyst with 40 wt. % alumina) had the highest dehydrogenation activity and suitable attrition resistance for the CFB reactor. Further investigation found that the adding alumina could inhabit the formation of KFe 11 O 17 , leading to poor stability. Interestingly, the high activity of the FeAl40 catalyst could be completely recovered through a reaction-regeneration operation. Compared with the conventional ethylbenzene dehydrogenation process, the CFB process benefits from high activity, low steam-to-oil ratio and no induction period. Consequently, the FeAl40 catalyst had high dehydrogenation activity (∼51 wt. % yield of styrene) and low preparation cost, showing an extraordinary potential for industrial application. [Display omitted] [ABSTRACT FROM AUTHOR]

[Display omitted] • A new bizeolite Pt/ZSM-5:ZSM-12/Al 2 O 3 catalyst was designed for C-8 aromatics isomerization. • ZSM-5/ZSM-12 based Pt catalyst allows both intra- and intermolecular isomerization routes. • Ethylbenzene and m -xylene conversions over ZSM-5+ZSM-12 based catalyst are higher than over an industrial counterpart. A bizeolite catalyst based on ZSM-5 and ZSM-12 was designed to maximize the yield of valuable aromatics from ethylbenzene (EB) rich feedstocks for the first time. The catalyst Pt/ZSM-5:ZSM-12/Al 2 O 3 was characterized by X-ray diffraction (XRD), nitrogen physisorption, temperature-programmed desorption of ammonia (TPD-NH 3), transmission and scanning electron microscopy (TEM and SEM), X-ray fluorescence analysis (XRF), Fourier-transformed infrared spectroscopy (FTIR) and 27Al magic angle spinning nuclear magnetic resonance (MAS NMR) spectroscopy. The catalyst and its components were tested in isomerization of an industrial C-8 aromatic cut (C8-Ar) and feedstocks with high EB content. The catalyst demonstrated higher conversion of EB and m -xylene (MX) compared with an industrial catalyst and higher selectivity to dealkylation products. [ABSTRACT FROM AUTHOR]

[Display omitted] • Synthesis of polymer-silica hybrid supported Co (II) and Cu (II) catalysts. • Characterization by BET, CHNS, SEM-EDX, FTIR, and TGA techniques. • Evaluation of catalytic activity by ethylbenzene oxidation at various reaction conditions. • Study of kinetic parameters and reusability test. Polymer-silica hybrid support (SA-2-AMPS-SiO 2) was synthesized and Co (II), Cu (II) metals were loaded over hybrid support by incipient impregnation technique. Oxidation of ethylbenzene was carried out for testing catalytic activity of catalysts at different reaction conditions i.e. the mole ratio of ethylbenzene to TBHP and reaction temperature. The main oxidation product was acetophenone along with benzaldehyde as the minor product and the highest ethylbenzene conversion (83.65 %) was attained at a 1:4 mol ratio of ethylbenzene to TBHP and temperature at 100 °C. The reusability of the catalysts was also determined and results showed that they can be easily reused three times without much loss in their structural and catalytic properties. [ABSTRACT FROM AUTHOR]

This paper is a numerical study about ethylbenzene (EB) dehydrogenation and nitrobenzene (NB) hydrogenation in a membrane reactor. Both sides of the membrane reactor were filled with an appropriate catalyst. Effect of different parameters in the dehydrogenation side including inlet temperature, pressure, catalyst porosity, and initial ethylbenzene concentration was investigated on temperature distribution and ethylbenzene and nitrobenzene conversion in the membrane reactor. Generally, the results showed that an increase in all parameters except the catalyst porosity can improve ethylbenzene and nitrobenzene conversion. The temperature was firstly decreased in the dehydrogenation side as the reactions were endothermic but there was an increase in temperature after a shorter distance from the entrance because of transferring heat from hydrogenation side into dehydrogenation side. Change in pressure has a considerable effect on the hydrogen transferring from dehydrogenation side into hydrogenation side. The styrene yield was not improved by increasing the initial ethylbenzene concentration from 5 to 20 mol/s but it has a positive influence on the yields of benzene and toluene. It was possible to achieve 0.97 of ethylbenzene conversion at 950 K. [Display omitted] • Numerical study of EB dehydrogenation and NB hydrogenation in a membrane reactor. • Study of temperature, pressure, and EB concentration effect on EB and NB conversion. • Rise in temperature and pressure and decrease in porosity enhances Styrene yield. [ABSTRACT FROM AUTHOR]

• Complex adsorption simulation is conducted by Grand Canonical Monte Carlo sets. • NH 3 -Zeolite RDF is conducted for acidity characterization. • Simulation of zeolite Pore Properties is investigated by Free and Skeleton Volume. • RDF is used for competitive adsorption and adsorbents interactions. • Prior of sites II is essentially for ethylbenzene adsorption on high SAR zeolites. The Si/Al molar ratio (SAR) of zeolites is crucial for separating unsaturated hydrocarbon components, but it was difficult to rule out the impact of changes in pore properties. In this work, a GCMC method was developed to investigate the effect of varying SAR (2.4, 20, and 50) using a module of NaY zeolite. The deviation of pore properties is less than 5%. When using ethylbenzene and n-octane as probe molecules, increasing the SAR is not conducive to improving the selectivity of ethylbenzene in single component adsorption, but in the two components, the selectivity increases from 76.0% to 92.6% when SAR increasing from 2.4 to 50. The increase of diffusion coefficient in two component is also significantly different. The NH 3 radial distribution functions (RDF) method was used to investigate the number of acid sites and acid strength, it can be observed that the adsorption capacity of ammonia decreases with SAR increasing but slightly when the SAR exceed 50. However, the number of ammonia molecules adsorbed per site significantly increases, the II site exhibits stronger acidity than III site. To distinguish different preferences of adsorbate onto zeolites with different SAR, concentration distribution combined with RDF was used. During single-component adsorption, both ethylbenzene and n-octane could be freely adsorbed on the II and III sites, however in binary situation, ethylbenzene tended on the II sites, while n-octane on the III sites. As the SAR increased, the adsorption of ethylbenzene, which displaced the original adsorption sites occupied by n-octane and consequently improved the selectivity of ethylbenzene. To investigate the interaction between adsorbents with different polarities, different feed concentration and RDF between the adsorbates were used, which revealed that polarities may have a greater impact on selectivity. Through the Monte Carlo series of tools, the structure-performance relationship between complex adsorbates and adsorbed molecules can be studied clearly. [ABSTRACT FROM AUTHOR]

A growing literature has reported associations between traffic-related air pollution and breast cancer, however there are fewer investigations into specific ambient agents and any putative risk of breast cancer development, particularly studies occurring in populations residing in higher pollution areas such as Los Angeles. To estimate breast cancer risks related to ambient air toxics exposure at residential addresses. We examined the relationships between ambient air toxics and breast cancer risk in the Multiethnic Cohort among 48,665 California female participants followed for cancer from 2003 through 2013. We obtained exposure data on chemicals acting as endocrine disruptors or mammary gland carcinogens from the National-Scale Air Toxics Assessment. Cox proportional hazards models were used to estimate breast cancer risk per one interquartile range (IQR) increase in air toxics exposure lagged by 5-years. Stratified analyses were conducted by race, ethnicity, and hormone receptor types. Among all women, increased risks of invasive breast cancer were observed with toxicants related to industries [1,1,2,2-tetrachloroethane (hazard ratio [HR] = 4.22, 95% confidence interval [95% CI] 3.18–5.60), ethylene dichloride (HR = 2.81, 95% CI 2.20–3.59), and vinyl chloride (HR = 2.27, 95% CI 1.81, 2.85); these 3 agents were correlated (r2 = 0.45–0.77)]. Agents related to gasoline production or combustion were related to increased breast cancer risk [benzene (HR = 1.32, 95% CI 1.24, 1.41), ethylbenzene (HR = 1.20, 95% CI 1.13–1.28), toluene (HR = 1.29, 95% CI 1.20–1.38), naphthalene (HR = 1.11, 95% CI 1.02–2.22), acrolein (HR = 2.26, 95% CI 1.92, 2.65)]. Higher hazard ratios were observed in African Americans and Whites compared to other racial and ethnic groups (p-heterogeneity <0.05 for traffic-related air toxics, acrolein, and vinyl acetate). Our findings suggest that specific toxic air pollutants may be associated with increase breast cancer risk. [ABSTRACT FROM AUTHOR]

Volatile organic compounds, such as BTEX, have been the subject of numerous debates due to their detrimental effects on the environment and human health. Human beings have had a significant role in the emergence of this situation. Even though US EPA, WHO, and other health-related organizations have set standard limits as unhazardous levels, it has been observed that within or even below these limits, constant exposure to these toxic chemicals results in negative consequences as well. According to these facts, various studies have been carried out all over the world – 160 of which are collected within this review article, so that experts and governors may come up with effective solutions to manage and control these toxic chemicals. The outcome of this study will serve the society to evaluate and handle the risks of being exposed to BTEX. In this review article, the attempt was to collect the most accessible studies relevant to risk assessment of BTEX in the atmosphere, and for the article to contain least bias, it was reviewed and re-evaluated by all authors, who are from different institutions and backgrounds, so that the insights of the article remain unbiased. There may be some limitations to consistency or precision in some points due to the original sources, however the attempt was to minimize them as much as possible. • This review article summarizes a wide range of studies on BTEX risk assessment. • The review takes an interdisciplinary approach from health, environmental sciences, and industrial studies on BTEX. • In the study, the effective solutions for management and control of BTEX are presented. • BTEX can interact with other pollutants in biosphere and exhibit synergistic effects leading to severe consequences. [ABSTRACT FROM AUTHOR]

• Micro-mesoporous TS-1 was synthesized by adding NaOH. • Reasonable inference of oxidation mechanism of p -diethylbenzene. • Addition of Na into zeolite skeleton improves the selectivity of products. The micro-mesoporous TS-1 catalyst was synthesized by directly introducing NaOH during the synthesis of zeolite. As the first choice for many oxidation reactions, TS-1/H 2 O 2 catalytic system is an environmentally friendly reaction system. However, the number and mechanism of Ti active sites participating in the reaction in TS-1 zeolite are seldom studied so far. Using TS-1 zeolite with and without NaOH as catalyst, p -diethylbenzene (PDEB) was oxidized in batch reactor to prepare p -ethylacetophenone and 1-(4-ethylphenyl)-1-ethanol. Reaction conditions including solvent, additives, temperature, time, dosage and oxidant were explored. The optimum reaction conditions, the conversion of PDEB was 27.7 % and the total selectivity was 74.5 % over TS-1-NaOH zeolite catalyst, where the selectivity of p -ethylacetophenone and 4-ethyl-α-methylbenzyl alcohol was 33.4 % and 41.1 %, respectively. Introducing mesoporous structure reduces the mass transfer resistance of the reaction and improves the selectivity of the target product. Based on the free radical reaction mechanism and the oxidative decomposition process of H 2 O 2 , it is inferred that the oxidation mechanism of PDEB in H 2 O 2 system is a free radical reaction with the participation of •O 2 −. [Display omitted] [ABSTRACT FROM AUTHOR]

Epidemiological evidence concerning effects of simultaneous exposure to noise and benzene, toluene, ethylbenzene, xylene, and styrene (BTEXS) on renal function remains uncertain. In 2020, a cross-sectional study was conducted among 1160 petrochemical workers in southern China to investigate effects of their co-exposure on estimated glomerular filtration rate (eGFR) and mild renal impairment (MRI). Noise levels were assessed using cumulative noise exposure (CNE). Urinary biomarkers for BTEXS were quantified. We found the majority of workers had exposure levels to noise and BTEXS below China's occupational exposure limits. CNE, trans, trans -muconic acid (tt -MA), and the sum of mandelic acid and phenylglyoxylic acid (PGMA) were linearly associated with decreased eGFR and increased MRI risk. We observed U-shaped associations for both N-acetyl-S-phenyl-L-cysteine (SPMA) and o-methylhippuric acid (2-MHA) with MRI. In further assessing the joint effect of BTEXS (β , −0.164 [95% CI, −0.296 to −0.033]) per quartile increase in all BTEXS metabolites on eGFR using quantile g-computation models, we found SPMA, tt -MA, 2-MHA, and PGMA played pivotal roles. Additionally, the risk of MRI associated with tt -MA was more pronounced in workers with lower CNE levels (P = 0.004). Multiplicative interaction analysis revealed antagonisms of CNE and PGMA on MRI risk (P = 0.034). Thus, our findings reveal negative dose-effect associations between noise and BTEXS mixture exposure and renal function in petrochemical workers. With the exception of toluene, benzene, xylene, ethylbenzene, and styrene are all concerning pollutants for renal dysfunction. Effects of benzene, ethylbenzene, and styrene exposure on renal dysfunction were more pronounced in workers with lower CNE. [Display omitted] • Noise exposure was associated with renal dysfunction in petrochemical workers. • BTEXS metabolites mixture was dose-dependently associated with eGFR decline. • SPMA, tt -MA, 2-MHA, and PGMA were key contributors to joint associations. • SPMA and 2-MHA exhibited nonlinear associations with renal dysfunction. • In workers with lower CNE, tt -MA and PGMA had stronger impacts on renal dysfunction. [ABSTRACT FROM AUTHOR]

A series of Cr-SiO 2 -Al 2 O 3 (abbreviated as Cr-Si-Al) catalysts were synthesized using an evaporation induced self-assembled (EISA) method and applied to the N 2 O-assisted dehydrogenation of ethylbenzene (EB), offering a versatile solution for greenhouse gas recycling and a novel pathway for styrene (ST) production. Notably, the Cr-5Si-Al catalyst calcinated at 850 °C exhibited remarkable performance with a high EB conversion of 71% and a good ST selectivity of 62%, resulting in an optimal ST yield of nearly 44%. To elucidate the impact of calcination temperature and reveal the underlying promoting mechanism, numerous types of characterization particularly in-situ DRIFTS were used. Results indicated that the Cr-5Si-Al-850 catalyst possessed a distinctively ordered mesoporous structure, which improved the specific surface area and facilitated the dispersion of active species. The interaction among the multiple species in the catalyst was enhanced under the high calcination temperatures, leading to an increased ratio of Cr6+ and O α , and thus promoting the dehydrogenation of EB. Furthermore, in situ DRIFTS revealed two favorable reaction pathways: one involving the reaction between adsorbed N 2 O and EB, and the other involving the reaction between adsorbed EB and N 2 O. These pathways led to the formation of a similar intermediate, observed at a wavenumber of 1285 cm−1. The improved adsorption of EB played a pivotal role in the excellent catalytic performance of the Cr-5Si-Al-850 catalyst. • The Cr-5Si-Al-850 catalyst exhibited superior catalytic performance for N2O-ODEB. • The Cr-5Si-Al-850 catalyst possessed an ordered mesoporous structure. • In situ DRIFTS revealed the formation of an intermediate at 1285 cm-1. • The improved adsorption of EB played a pivotal role in the excellent catalytic performance. [ABSTRACT FROM AUTHOR]

Alkylbenzenes constitute a significant portion of middle-distillate transportation fuels, and they are judged as the key contributors to the extent of soot production and consequent exhaust particulate emissions in combustion engines. Because of the uncertainties involved in engine experiments due to boundary condition variation among test platforms and the difficulties involved in controlling engine variables independently, benchmark information on pressure dependence of sooting propensities of alkylbenzenes is essential to understand their influence on particulate emissions and provide a more consistent interpretation of engine data. One of the approaches to acquire such benchmark data is to investigate laminar diffusion flames doped with alkylbenzenes under tractable conditions at elevated pressures. Here, we study the influence of doping a methane laminar diffusion flame with alkylbenzenes having eight carbon atoms, namely ethylbenzene, p -xylene, and o -xylene and compare their sooting characteristics to that of n -octane at pressures up to 10 bar. Liquid hydrocarbons added to methane replaced 3% of the carbon in the base fuel keeping the carbon mass flow in the fuel stream fixed, at all pressures considered, to have tractable measurements. The flames of base fuel methane and those doped with liquid C 8 hydrocarbons were stabilized on a laminar co-flow diffusion burner positioned inside a combustion chamber capable of elevated pressures and has suitable optical access. Radially resolved temperatures and soot volume fractions were evaluated from spectral emission of soot radiation from the flames. Soot yields, inferred from the radial distributions of soot volume fractions, of ethylbenzene, p -xylene, and o -xylene doped flames were found to be a factor of about 2.6–3.2 higher than that of n -octane at 2 bar; however, this difference gradually disappeared with increasing pressure and soot yields were almost the same above 6 bar. It appears that pressure dependence of sooting propensities of ethylbenzene, p -xylene, and o -xylene is weaker than that of n -octane within the pressure range of 2 to 10 bar. [ABSTRACT FROM AUTHOR]

• Monitoring the "breathing effect" in MIL-53(Cr) under the liquid phase adsorption. • Preference reversal between p-xylene and m-xylene in MIL-53(Cr). • Increasing the selectivity of xylene isomers to ethylbenzene in re-opened MIL-53(Cr). • Microscopic explanations of the interaction between water molecules and C8 aromatics. The flexible metal-organic framework MIL-53(Cr) has been demonstrated to be an efficient adsorbent for liquid phase adsorption and separation, while the effect of this attractive "breathing effect" on its performance remains uncertain. In this research, by increasing the amount of introduced water, MIL-53(Cr) first shrank into a narrow pore form through bound water and then reopened due to the introduction of free water. Using MIL-53(Cr) with diverse amounts of water as an adsorbent, the liquid-phase adsorption and separation of C8 aromatics, including o -xylene (OX), p -xylene (PX), m -xylene (MX) and ethylbenzene (EB), was manipulated by the pre-adsorbed water in MIL-53(Cr). Pre-adsorbing water in MIL-53(Cr) induced a preference reversal between MX and PX, where dry samples preferentially adsorbed MX, while high-water-addition samples preferred PX instead. In addition, the reopened MIL-53(Cr) with high water addition hardly adsorbed EB, thereby increasing the selectivity of xylene isomers to EB. A longer equilibrium time was observed on MIL-53(Cr) with high water addition, during which the adsorption preference shifted from OX to MX to PX. Further molecular simulation provided a microscopic explanation that water molecules in the pores tended to package around MX and EB, hindering their interaction with frameworks or other adsorbates. Using MIL-53(Cr) with diverse amount of water addition as adsorbents, the liquid-phase adsorption and separation of C8 aromatics including o-xylene (OX), p-xylene (PX), m-xylene (MX) and ethylbenzene (EB) was manipulated by pre-adsorbed water in MIL-53(Cr), which was explained by experimental characterization on the frameworks and further theoretical molecular simulation at a molecular level. [Display omitted] [ABSTRACT FROM AUTHOR]

Iron-containing garnets (YIG) were used as catalysts for selective oxidation of ethylbenzene (EB) in the presence of H 2 O 2 as oxidant. The catalysts comprising of two series of garnets e.g., Y 3 (Fe 1–x Zn x) 5 O 12 and Y 3 (Fe 1–x Ni x) 5 O 12 had distinct Zn and Ni contents (x = 0.00 0.01, 0.03, and 0.05). XRD, Raman and FTIR spectroscopies revealed that the cubic structure of Y 3 Fe 5 O 12 garnet was present for x = 0.00 and 0.01. For higher contents, the garnets had the Y 3 Fe 5 O 12 phase besides hematite (α-Fe 2 O 3). The catalytic activity was dependent on the contents of metals in the garnets with Y 3 Fe 4·97 Ni 0·03 O 12-γ and Y 3 Fe 4·9 5 Zn 0·05 O 12-γ catalysts achieving better results. The influence of the reaction conditions such as reaction time, reaction temperature and effect of the solvents as well as the substrates to H 2 O 2 molar ratios were studied. SEM-EDS, XPS and EPR results demonstrated the affinity of the Fe2+/Fe3+ pairs with Ni2+ species for the ethylbenzene molecule, which gave an EB conversion of 77% with a good production of acetophenone over the Y 3 Fe 4·97 Ni 0·03 O 12-γ catalyst compared to other binary and ternary solids. [ABSTRACT FROM AUTHOR]

• Fe 2 O 3 promoted the performance of TiO 2 -ZrO 2 catalyst for EB dehydrogenation. • An induction period was observed with TOS due to the reduction of Fe 2 O 3 species. • A CFB process proposed can realize continuous reaction-regeneration operation. • A conceptual EB dehydrogenation process was proposed to decrease operation cost. In conventional ethylbenzene dehydrogenation process, abundant superheated steam is consumed to supply reaction heat and inhibit coke formation, thereby a high operation cost is resulted. In this work, Fe 2 O 3 promoted TiO 2 -ZrO 2 catalyst demonstrated outstanding dehydrogenation performance in the absence of steam. The catalyst composition and preparation method have both been studied and optimized. The high specific surface area, well dispersion of Fe 2 O 3 species, and appropriate acid-base properties are all necessary for ethylbenzene dehydrogenation. Ascribed to the reduction of Fe 2 O 3 species, an induction period to reach the highest styrene selectivity was observed. For the catalyst after pre-reduction, an outstanding initial dehydrogenation performance can be obtained and kept stable in eight reaction-regeneration cycles. Further, a conceptual fluidized-bed ethylbenzene dehydrogenation process composed of a reactor, a regenerator and a reduction section was proposed to realize continuous reaction-regeneration operation. This work not only provides a class of ethylbenzene dehydrogenation catalyst efficient in the absence of steam, but also presents the concept of fluidized bed process obviously reducing the operation cost and achieving self-heat balance. [Display omitted] [ABSTRACT FROM AUTHOR]

This work presents a comparative study on the pyrolysis of C 8 –C 10 linear alkylbenzenes including ethylbenzene, n -propylbenzene and n -butylbenzene. Experiments were performed with highly diluted mixtures in argon containing respectively the three fuels under nearly identical conditions in a single-pulse shock tube, at a nominal pressure of 20 bar and over a temperature range of 950–1700 K. Post-shock gas mixtures were sampled and analyzed with the gas chromatographic technique so that species concentration evolutions as function of temperature were obtained for the pyrolysis of each fuel. A kinetic model was developed to interpret the similarities and differences regarding the fuel decomposition and species formation behaviors observed in the experiments. The fuel conversion of n -propylbenzene and n -butylbenzene proceeds along a similar curve, which is much faster than that of ethylbenzene. All three fuels are consumed mainly through the bond fission producing benzyl radical. The simultaneously formed C 1 –C 3 alkyl radicals in separate cases significantly impact the fuel reactivity and the formation of small C 1 –C 4 and monocyclic aromatic hydrocarbons. Specifically, in n -propylbenzene pyrolysis, the decomposition of ethyl radicals produces a considerable amount of hydrogen atoms, which enhances the reactivity of the reaction system and meanwhile results in relatively high production of benzene during the fuel consumption. The formation of other monocyclic aromatic hydrocarbon intermediates, such as toluene and styrene, is also influenced by fuel-related pathways. Concerning PAH formation, the kinetic schemes in the pyrolysis of linear C 8 –C 10 alkylbenzenes are very similar, which are dominated by the reactions of benzyl and other resonantly-stabilized radicals produced from benzyl decomposition. The major PAH formation reactions are barely influenced by the fuel chemistry. The only notable fuel-specific pathway is the indene formation from 1-phenyl-2-propenyl in n -propylbenzene and n -butylbenzene pyrolysis at relatively low temperatures. Styrene is an abundant product and its reaction with phenyl is found to be an important channel of phenanthrene formation. [ABSTRACT FROM AUTHOR]

Pressure membrane processes such as nanofiltration (NF) play an important role in purifying water, from which not only inorganic substances but also petroleum-derived organic compounds can be removed. The study evaluated the removal of petroleum hydrocarbons from water using nanofiltration. The work was carried out applying a spiral module equipped with a commercial NF-212 membrane. Model water was used for the study. Determinations of studied petroleum aliphatic hydrocarbons from C7 to C33 and monoaromatic hydrocarbons were performed on a gas chromatograph coupled with a mass spectrometer. Quantitative analysis was performed using the calibration curve method. During the process, the retention factor, volumetric flow of deionized water (Jw), both before and after the process and volumetric flow of model water permeate were calculated, and the relative membrane permeability value for the deionized water stream aw and the relative membrane permeability for the model water stream av was calculated. [ABSTRACT FROM AUTHOR]

Surgical smoke produced by electrosurgery contains various chemical substances such as volatile organic compounds (VOCs) and polycyclic aromatic hydrocarbons (PAHs). The aim of this study is to investigate airborne concentrations of VOCs and PAHs during electrosurgery in an operating room, in relation to metabolites in urine in order to assess the absorbed dose. A 5-day exposure study was set up in a general surgery operation room including surgeons, scrub assistants and circulation nurses (n = 15). Stationary and personal air sampling for VOCs and PAHs were carried out. Pre-, mid- and end-shift analysis of urinary S-phenylmercapturic acid (SPMA), o-cresol, mandelic acid and 1-hydroxypyrene was performed to assess the internal exposure to respectively benzene, toluene, styrene and PAHs. Several VOCs (styrene, ethyl benzene, benzene and toluene), ranging from 0.7 to 3.27 μg/m3 were detected in the air samples, along with one PAH (naphthalene, ranging from 0.012 to 0.39 μg/m 3). There was no significant correlation between air monitoring and urinary biomonitoring. O-cresol levels were increased, especially among assistants and nurses at mid- and end-shift, exceeding current biological exposure indices several times. External and internal exposure for assistants and nurses was substantially more, compared to surgeons. This study confirms the presence of VOCs and PAHs in surgical smoke and shows the presence of their metabolites in urine, but the association is unclear. Urinary biomonitoring shows especially high concentrations of o-cresol. [ABSTRACT FROM AUTHOR]

• BTEXs and their spatial distribution, source identification and risk assessment were analyzed. • The ILCR for benzene and ethylbenzene were 6.49 × 10−7-1.27 × 10-5 and 1.21 × 10−7- 2.37 × 10-6. • Strong correlation among individual BTEXs suggests that traffic is the main source contributing. The present study aimed to assess BTEX (benzene, toluene, ethylbenzene, and xylenes) concentrations, their sources and health risk estimates in Shiraz, the fifth-most populous city in Iran. Air samples were collected from 19 sampling stations across Shiraz using passive samplers. Identification and quantification of BTEX were conducted by a Gas Chromatography–Mass Spectrometry (GC–MS). Spatial distribution of BTEX compounds were mapped by inverse distance weighting (IDW) procedure. Monte Carlo simulation was employed to assess the corresponding carcinogenic and non-carcinogenic risks of BTEX concentrations. BTEX concentrations were higher than current levels in Western countries but lower than concentrations measured in East Asia. Analysis of individual BTEX ratios and their strong correlation indicated that fresh traffic emissions were the main contributor to these compounds in Shiraz, with additional sources contributing to toluene (e.g. industrial solvent use) and benzene (e.g. evaporative emissions). The incremental lifetime cancer risk (ILCR) for benzene and ethylbenzene were estimated to be 6.49 × 10−7- 1.27 × 10-5 and 1.21 × 10−7- 2.37 × 10-6, respectively, exceeding the WHO and EPA recommendations. The current evaluation of BTEX sources and associated health risks will assist policymakers to define action plans to minimize BTEX exposure in Shiraz and similar cities in the Middle East. [ABSTRACT FROM AUTHOR]

Herein, N-doped graphene quantum dots (NGQDs) were prepared in an environmentally friendly manner using different sonication conditions by varying two important operating parameters: ultrasonic amplitude and sonication duration. In addition, they were decorated onto FeWO 4 /g-C 3 N 4 heterostructures to afford a NGQD/FeWO 4 /g-C 3 N 4 ternary-nanocomposites (NGQD/FWO/CN), which were tested for the photocatalytic removal of noxious vapors. The surface properties of the NGQDs varied with the sonication duration and the ultrasonic amplitude, and the photocatalytic capability of NGQD/FWO/CN varied with the type of decorated NGQDs, which were defined based on the sonication conditions. Moreover, the photocatalytic capability of FeWO 4 /g-C 3 N 4 heterostructures decorated with sonication-treated NGQDs was higher than that of those decorated with NGQDs prepared without a sonication process. NGQD/FWO/CN also exhibited higher photocatalytic efficiency compared with selected photocatalyst counterparts, most likely due to the upconversion photoluminescence properties of NGQDs and the charge-separation abilities promoted by the electron-affinitive NGQDs and by the Z-scheme carrier-transport progress at the interfaces between the g-C 3 N 4 and FeWO 4. Specifically, the average removal efficiencies of vaporous 2-butoxy ethanol and ethyl benzene over a representative NGQD/FWO/CN sample under specified operational conditions were 97.3% (±0.7%) and 55.1% (±0.6%), respectively. Moreover, the pollutant removal capabilities of the photocatalysts were in accordance with their photocurrent measurements. The ternary nanocomposite also revealed excellent photocatalytic stability after successive uses for the decomposition of the model contaminants. Overall, this study highlights the promising role of nanocomposites decorated with sonication-processed NGQDs as photocatalysts for the efficient removal of noxious vapors. • Decoration of sonicated NGQDs onto FeWO 4 /g-C 3 N 4 improved photocatalytic capability. • Ultrasonic amplitude and sonication duration influenced the photocatalytic capability. • Intrinsic properties of NGQDs and Z-scheme charge transfer raised catalyst capability. • NGQD-decorated FeWO 4 /g-C 3 N 4 revealed the feasibility of its prolonged use. • Composite decorated with sonication-processed NGQDs efficiently remove noxious vapors. [ABSTRACT FROM AUTHOR]

FeCuCo over aluminum oxide catalyst was prepared to catalytically degrade polystyrene (PS) into ethylbenzene (EB) under mild conditions. This catalyst was characterized by XRD, SEM, STEM-EELS, STEM-EDS, XPS, and physical properties. A significant selectivity toward EB formation at 250 °C was achieved in the absence of hydrogen with 82% liquid yield. End-chain session and cross-linking reactions are proposed to be the dominant pathways in the degradation of PS over FeCuCo to form EB. [ABSTRACT FROM AUTHOR]

[Display omitted] • A nanostructure complex [Mn (pzo) 2 (H 2 O) 2 ] (MS) was synthesized under ultrasonic irradiation. • [Mn (pzo) 2 (H 2 O) 2 ] (MR) was synthesized under reflux. • MS and MR were used as catalysts in the peroxidative conversion of EB. • In the optimum conditions, the maximum EB conversion of 91 % was attained for MS. • A free radical mechanism was proposed for the oxidation of EB in the presence of MS and MR. An inorganic complex of Mn(II) formulated as [Mn(pzo) 2 (H 2 O) 2 ] where pzo = Pyrazonic acid has been synthesized using two different methods; under ultrasonic irradiation as precipitate (MS) and by reflux as single crystal (MR). The structure of MR was characterized by single crystal X-ray diffraction (SC-XRD). The results of SC-XRD analysis exhibited that MR crystallizes in space group Fdd2 of an orthorhombic system and the centers of Mn2+ adopted a distorted octahedral geometry. MS and MR complexes were characterized by elemental analysis (CHN), atomic absorption spectroscopy (AAS), inductively coupled plasma optical emission spectrometry (ICP-OES), energy-dispersive X-ray spectroscopy (EDXS or EDS), X-ray photoelectron spectroscopy (XPS), Fourier-transform infrared spectroscopy) FT-IR (, powder X-ray diffraction (PXRD), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), scanning electron microscopy (SEM), and Brunner-Emmet-Teller (BET). The results of CHN, AAS, ICP-OES, EDS, XPS, FT-IR and TGA/DTA analyses showed that MR and MS complexes have the same structures. The results of PXRD, SEM, and BET analysis showed that the MR and MS have different particle size, morphology, and textural properties. The MR and MS were used as homogeneous catalysts in the solvent-free oxidation of ethylbenzene (EB) to acetophenone (AP) and benzaldehyde (BA) in the presence of tert -butyl hydroperoxide (TBHP) as an oxidant. Solvent-free oxidation of ethylbenzene is an environmentally friendly method since it does need a solvent. The maximum conversion efficiency in the optimum operating conditions for MS and MR was 86.5 and 71.5 %, respectively. Finally, a free radical mechanism was proposed for the oxidation of ethylbenzene in the presence of MS and MR. [ABSTRACT FROM AUTHOR]

• Reaction mechanism of plasma-enabled aromatic ring hydrogenation is proposed. • H 2 plasma shows greater potential in hydrogenation than CH 4 plasma. • Role of H radicals in the process of hydrogenation and cleavage is examined. • Radical recombination competes strongly with aromatic ring hydrogenation. • Oscillation of H number added to the ring indicates a limitation in hydrogenation. Plasma hydrogenation technology represents a sustainable and environment-friendly solution to upgrade heavy oil, but the underlying mechanisms of plasma hydrogenation for heavy oil or its model compounds remain insufficiently understood. Here we demonstrate the utilization of hydrogen-rich plasma for the hydrogenation of heavy oil model compound ethylbenzene under ambient conditions without catalysts, highlighting the crucial role of free radicals in this process. Simulation results show that H 2 plasma yields a higher density (1.98 × 1014 vs 1.06 × 1014 cm−3) and slower consumption rate (1.0 × 1016 vs 2.5 × 1018 cm−3 s−1) of H radicals, and a higher average H number (1.8–4.3 vs 0.5–1.7) added to the aromatic ring, leading to a more efficient hydrogenation of aromatic rings compared to CH 4 plasma. Moreover, an increase in H radical density may result in the cleavage of hydrogenated products due to elevated high-energy electron levels, hence potentially undermining the overall effectiveness. Experimental results further reveal that radical recombination is the dominant reaction mechanism for H-involved reactions, since almost no hydrogenated products were observed after CH 4 plasma treatment. These novel insights into plasma-enabled aromatic ring hydrogenation provide a new and green approach for future upgrading of heavy oils. [ABSTRACT FROM AUTHOR]

• Probing benzene, toluene, ethylbenzene, and xylenes (BTEX) at their bending mode regions provides unprecedented selectivity. • Difference-frequency-generation laser-source was used to access the bending modes of BTEX. • Excellent performance and wide dynamic range were achieved using the custom-designed sensor. • Detection limits achieved were: 60, 15, 40, and 50 ppm for benzene, toluene, ethylbenzene, and m -xylene, respectively. BTEX (benzene, toluene, ethylbenzene, and xylene) are simple aromatics that play a major role in soot formation in combustion systems. They are widely used as aromatic representatives in fuel surrogates. Measuring BTEX in chemical reactors can give insight into the soot formation mechanisms and help mitigate its production. The similar chemical structures of BTEX make their selective detection highly challenging. These species give rise to broad and similar absorption features across most of the electromagnetic spectrum. In this work, we report the development of a selective BTEX laser-based sensor in the long-wave mid-infrared (LW-MIR) spectral region. The sensor probes the rarely accessed CH bending modes of BTEX molecules and takes advantage of the strong, spectrally isolated absorption features of aromatics in this spectral region. The developed sensor is based on a custom-designed difference-frequency generation (DFG) laser source. Wavelength selection, and the development and evaluation of the performance of the custom-designed sensor are discussed. The sensor was found to perform excellently over the mole fraction range of 0 - 1,000 ppm of each of the BTEX species. Estimated detection limits of our developed sensor are 60, 15, 40, and 50 ppm for benzene, toluene, ethylbenzene, and m -xylene, respectively. [ABSTRACT FROM AUTHOR]

A simple and adaptable synthetic method is reported here for synthesizing UiO-66-GO nanohybrid materials by modulating the growth and dispersion of UiO-66 on GO surfaces, using PdCl 2 as the Pd source with thermal treatment at 120 °C without additional reduction to obtain Pd/UiO-66-rGO composite catalyst. Pd/UiO-66-rGO demonstrates excellent activity in catalytic transfer hydrogenation for C═C bond of aromatic alkenes by using HCOONH 4 and water as hydrogen donor and solvent at 25 °C, with 99.6 % styrene conversion and 99.9 % selectivity to ethylbenzene. The confinement effect leads to ultra-small Pd NPs active sites evenly dispersed on Pd/UiO-66-rGO, which is the good catalytic performance of Pd/UiO-66-rGO results from. Additionally, UiO-66-rGO makes a protection effect to stabilize and prevent the Pd active sites leaching out, ensuring the cyclic stability of this catalyst. [Display omitted] [ABSTRACT FROM AUTHOR]

[Display omitted] • VOCs from soil thermal desorption were treated via wet scrubbing coupled with AOPs. • MnCoO x /Kaolin were synthesized via cation-exchange based impregnation-calcination. • Continuous dosing of oxidant was designed and compared in wet-scrubber system. • The stability of VOCs removal rate and mineralization rate was enhanced. • SO 4 · - was proposed to be reactive species responsible for benzene degradation. The heterogeneous advanced oxidation processes coupling with wet scrubber is a promising method for the treatment of VOCs produced by soil thermal desorption. Mn-Co bimetallic oxides/Kaolin (MnCoO x /Kaolin) were successfully synthesized via cation-exchange based impregnation-calcination. The abundant SiO-OH and AlO-OH groups on the Kaolin carrier can inhibit metal aggregation, and the synergistic effect between Kaolin and metal oxide can improve the catalytic performance. The removal rate of benzene via wet scrubber with MnCoO x /Kaolin as catalyst remained above 98 %, which was better than that of single metal oxide. Moreover, the system exhibited significant application effects on the single component (toluene, ethylbenzene, xylene) and BTEX mixture, with the removal rates maintaining at higher than 90 %. The dosing method of PMS was optimized, and the method of continuous dosing of oxidant was proposed instead of one-time dosing. The main active oxygen in the MnCoO x /Kaolin system was sulfate radical, as shown by the results of characterization analysis and quenching experiments. Based on the intermediates identified by GC–MS, a possible degradation pathway of benzene in MnCoO x /Kaolin + PMS system was proposed. [ABSTRACT FROM AUTHOR]

[Display omitted] • The stable P-silicane nanosheet possesses an energy gap of 3.964 eV. • The novel P-silicane sheets are used as base material to adsorb ethylbenzene and ethylene glycol molecules. • The P-silicane sheets exhibit chemi-resistive property upon adsorption of ethylbenzene and ethylene glycol molecules. • The outcome indicates that novel P-silicane sheets can be used as chemosensor towards ethylbenzene and ethylene glycol molecules. Silicene is one among various two-dimensional (2D) materials that is gaining the spotlight owing to its fascinating applications in different fields. In the present work, we report the adsorption characteristics of ethylbenzene and ethylene glycol on a novel P-silicane nanosheet. Moreover, with the formation energy of − 4.836 eV/atom, it is inferred that P-silicane is structurally stable. Besides, the electronic properties of P-silicane get modified owing to the adsorption of ethylbenzene and ethylene glycol molecules. The pristine P-silicane possesses an energy gap of 3.965 eV. The results show the electro-resistive nature of P- silicane due to the adsorption of ethylbenzene and ethylene glycol. The outcome of the proposed work supports the deployment of P-silicane for the detection of ethylbenzene and ethylene glycol, which are emitted from the chemical industry. [ABSTRACT FROM AUTHOR]

Styrene is an important building block of the plastics industry being produced by ethylbenzene dehydrogenation. The commercial catalysts have the disadvantages of deactivation by potassium loss and coke deposition, and chromium toxicity. To overcome these drawbacks, a new catalyst was developed by investigating the effect of magnesium on the catalytic properties of hematite in ethylbenzene dehydrogenation. Hematite was detected for all fresh catalysts and magnetite for the spent ones. Magnesium was found as magnesium ferrite and magnesium oxide, depending on the magnesium amount. Magnesium compounds affect the crystal sizes, the amount of defects and the reducibility of iron oxides, the predominance of each one depending on the composition of the solids. These effects caused important differences in activity, selectivity and stability of the catalysts. The catalyst with Mg/Fe = 0.09, consisting of aggregates of hematite, MgO and magnesium ferrite, showed the highest yield, being the most promising for commercial applications. [Display omitted] • Magnesium makes the reduction of hematite to magnetite easier. • Magnesium oxide acts as a spacer, limiting the growth of hematite crystallites. • Magnesium ferrite increases activity by electronic interactions. • Magnesium oxide increases hematite activity by decreasing the size particle. • Styrene is selectively produced using magnesium-doped hematite as catalyst. [ABSTRACT FROM AUTHOR]

The difference of peroxide decomposition on carbon nitrides (CNx) supported the transition-metal oxide catalysts is the key to EB oxidation activity and product selectivity. [Display omitted] • Ethylbenzene (EB) oxidation catalyzed by transition-metal oxides catalysts is performed. • Co 3 O 4 /CN x displays the highest activity and considerable acetophenone(AcPO) selectivity. • CuO/CN x shows the moderate activity and highest AcPO selectivity. • The difference of peroxide decomposition on catalyst is the key to EB oxidation activity and product selectivity. Selective oxidation of aromatics via a free-radical process is a crucial ingredient in the chemical industry, in which the transformation of hydroperoxide was considered the key step to facilitate the reaction. In this study, the aerobic oxidation of ethylbenzene (EB) to acetophenone (AcPO) catalyzed by carbon nitrides (CN x) supported the transition-metal oxides was performed. Among these catalysts, Co 3 O 4 /CN x displayed the highest activity with 48.09 % EB conversion and 77.8 % AcPO selectivity, due to the efficient decomposition of 1-phenylethyl hydroperoxide (PEHP). Notably, in the case of CuO/CN x , the relatively low EB conversion (19.8 %) and high selectivity of AcPO (70.2 %) were observed, while almost no PEHP was detected. Further mechanism investigations revealed that the decomposition of hydroperoxide over CuO/CN x was too fast to generate the reactive free-radicals, which could not efficiently facilitate the propagation steps. Moreover, the addition of tert -butyl hydroperoxide (TBHP) participated in the α-H abstraction of EB and facilitated of radical propagation, showing the distinguished activities over Co 3 O 4 /CN x and CuO/CN x. [ABSTRACT FROM AUTHOR]