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The selective hydrogenation of the biomass platform molecule furfural (FAL) to produce furfuryl alcohol (FA) is of great significance to alleviate the energy crisis. Cu-based catalysts are the most commonly used catalysts, and their catalytic performance can be optimized by changing the preparation method. This paper emphasized the effect of calcination atmosphere on the performance of a Cu/Al2O3 catalyst for the selective hydrogenation of FAL. The precursor of the Cu/Al2O3 catalyst prepared by the ammonia evaporation method was treated with different calcination atmospheres (N2 and air). On the basis of the combined results from the characterizations using in situ XRD, TEM, N2O titration, H2-TPR and XPS, the Cu/Al2O3 catalyst calcined in the N2 atmosphere was more favorable for the dispersion and reduction of Cu species and the reduction process could produce more Cu+ and Cu0 species, which facilitated the selective hydrogenation of FAL to FA. The experimental results showed that the N2 calcination atmosphere improved the FAL conversion and FA selectivity, and the FAL conversion was further increased after reduction. Cu/Al2O3-N2-R exhibited the outstanding performance, with a high yield of 99.9% of FA after 2 h at 120 °C and an H2 pressure of 1 MPa. This work provides a simple, efficient and economic method to improve the C=O hydrogenation performance of Cu-based catalysts. [ABSTRACT FROM AUTHOR]

Roasting is an important step in the pretreatment of biomass upgrading. Roasting can improve the fuel quality of biomass, reduce the O/C and H/C ratios in the biomass, and provide the biomass with a fuel quality comparable to that of lignite. Therefore, studying the structure and component evolution laws during biomass roasting treatment is important for the rational and efficient utilization of biomass. When the roasting temperature is 200–300 °C, the cellulose and hemicellulose in the biomass undergo a depolymerization reaction, releasing many monocyclic aromatic hydrocarbons with high reactivity. The proportion of monocyclic aromatic hydrocarbons in biomass roasting products can be effectively regulated by controlling the reaction temperature, residence time, catalyst, baking atmosphere, and other factors in the biomass roasting process. This paper focuses on the dissociation law of organic components in the pretreatment process of biomass roasting. [ABSTRACT FROM AUTHOR]

Phospholane-phosphites are known to show highly unusual selectivity towards branched aldehydes in the hydroformylation of terminal alkenes. This paper describes the synthesis of hitherto unknown unsaturated phospholene borane precursors and their conversion to the corresponding phospholene-phosphites. The relative stereochemistry of one of these ligands and its Pd complex was assigned with the aid of X-ray crystal structure determinations. These ligands were able to approach the level of selectivity observed for phospholane-phosphites in the rhodium-catalysed hydroformylation of propene. High-pressure infra-red (HPIR) spectroscopic monitoring of the catalyst formation revealed that whilst the catalysts showed good thermal stability with respect to fragmentation, the C=C bond in the phospholene moiety was slowly hydrogenated in the presence of rhodium and syngas. The ability of this spectroscopic tool to detect even subtle changes in structure, remotely from the carbonyl ligands, underlines the usefulness of HPIR spectroscopy in hydroformylation catalyst development. [ABSTRACT FROM AUTHOR]

Glycerol is a main by-product of biodiesel production, and its further processing is essential for the biorefinery. In this paper, a highly active and stable catalyst for the catalytic dehydration of glycerol to acetol is obtained by modifying a Cu-Zr (ZrO2 supported Cu) catalyst with Y2O3 using a co-precipitation method. It is found that the addition of Y2O3 effectively enhances the catalytic performance of Cu-Zr. Cu-Zr reaches the highest selectivity (82.4%) to acetol at 24 h. However, the selectivity decreases to 70.1% at 36 h. The conversion also decreases from 99.2 to 91.1%. Cu-Zr-Y exhibits very high activity and very good stability. During a 250 h reaction, no deactivation is observed, and the conversion and selectivity remains ~100% and ~85%, respectively. The catalysts are characterized by XRD, TEM, H2-TPR, and NH3-TPD. The results reveal that Y2O3 not only improves the dispersion of Cu and the acidity of the catalyst but also restrains the agglomeration of Cu particles and assists retaining the main structure of support under reaction conditions. The high dispersion, high acidity content, and stable structure contributes to the excellent catalytic performance of Cu-Zr-Y. [ABSTRACT FROM AUTHOR]

In recent years, the non-petroleum production of light olefins has been the research focus of Fischer–Tropsch olefin synthesis (FTO). Iron-based catalysts have attracted much attention because of their low price, high catalytic activity, and wide temperature range. In this paper, traditional modification, hydrophobic modification, and amphiphobic modification of the catalyst are summarized and analyzed. It was found that traditional modification (changing the pore size and surface pH of the catalyst) will reduce the dispersion of Fe, change the active center of the catalyst, and improve the selectivity of light olefins (for example, SiO2: 32%). However, compared with functional methods, these traditional methods lead to poor stability and high carbon dioxide selectivity (for example, SiO2: 34%). Hydrophobic modification can inhibit the adsorption and retention of water molecules on the catalyst and reduce the local water pressure near the iron species in the nuclear layer, thus inhibiting the further formation of CO2 (for example, SiO2: 5%) of the WGSR. Amphiphobic modification can not only inhibit the WGSR, but also reduce the steric hindrance of the catalyst, increase the diffusion rate of olefins, and inhibit the reabsorption of olefins. Follow-up research should focus on these issues. [ABSTRACT FROM AUTHOR]

Oil is the "blood" and economic lifeblood of modern industry, but traditional light crude oil has been over-consumed, and it has been difficult to meet human demand for energy, so the exploitation of heavy oil is particularly important. In this paper, an oil-soluble catalyst was synthesized to catalyze the pyrolysis reaction of heavy oil in collaboration with reservoir minerals, so as to achieve efficient viscosity reduction of heavy oil and reduce production costs. The experimental results showed that Zn(II)O + K had the best synergistic viscosity reduction effect after the aquathermolysis of No. 1 oil sample under the reaction conditions of 180 °C, 4 h, 30% of water, and 0.2% of catalyst, respectively, and the viscosity reduction rate was 61.74%. Under the catalysis of the isopropanol system, the viscosity reduction rate was increased to 91.22%. A series of characterizations such as freezing point, thermogravimetric analysis, DSC analysis, component analysis, gas chromatography, wax crystal morphology analysis, and GC-MS analysis of aqueous organic matter were carried out on heavy oil after reaction by different reaction systems, and it could be verified that the viscosity of heavy oil was reduced. Finally, through the study of the reaction mechanism of the model compound, combined with the aqueous phase analysis, it can be clearly found that the depolymerization between macromolecules, the breaking of heteroatom chains, hydrogenation, ring opening, and other effects mainly occur during the reaction, thereby weakening the van der Waals force and hydrogen bond of the recombinant interval, inhibiting the formation of grid structure in heavy oil and effectively reducing the viscosity of heavy oil. [ABSTRACT FROM AUTHOR]

In this Special Issue, "Featured Papers in Organometallic Chemistry", we report on the synthesis and characterization of [IPr#–PEPPSI], a new, well-defined, highly hindered Pd(II)–NHC precatalyst for cross-coupling reactions. This catalyst was commercialized in collaboration with MilliporeSigma, Burlington, ON, Canada (no. 925489) to provide academic and industrial researchers with broad access to reaction screening and optimization. The broad activity of [IPr#–PEPPSI] in cross-coupling reactions in a range of bond activations with C–N, C–O, C–Cl, C–Br, C–S and C–H cleavage is presented. A comprehensive evaluation of the steric and electronic properties is provided. Easy access to the [IPr#–PEPPSI] class of precatalysts based on modular pyridine ligands, together with the steric impact of the IPr# peralkylation framework, will facilitate the implementation of well-defined, air- and moisture-stable Pd(II)–NHC precatalysts in chemistry research. [ABSTRACT FROM AUTHOR]

As a clean and renewable energy source for sustainable development, hydrogen energy has gained a lot of attention from the general public and researchers. Hydrogen production by electrolysis of water is the most important approach to producing hydrogen, and it is also the main way to realize carbon neutrality. In this paper, the main technologies of hydrogen production by electrolysis of water are discussed in detail; their characteristics, advantages, and disadvantages are analyzed; and the selection criteria and design criteria of catalysts are presented. The catalysts used in various hydrogen production technologies and their characteristics are emphatically expounded, aiming at optimizing the existing catalyst system and developing new high-performance, high-stability, and low-cost catalysts. Finally, the problems and solutions in the practical design of catalysts are discussed and explored. [ABSTRACT FROM AUTHOR]

Known as electrophiles, maleimides are often used as acceptors in Michael additions to produce succinimides. However, reactions with maleimides as nucleophiles for enantioselective functionalization are only rarely performed. In this paper, a series of bifunctional Takemoto's catalysts were used to organocatalyze the enantioselective Michael reaction of aminomaleimides with nitroolefins. The resulting products were obtained in good yields (76–86%) with up to 94% enantiomer excess (ee). The catalyst type and the substrate scope were broadened using this methodology. [ABSTRACT FROM AUTHOR]

Non-noble metal-based bifunctional electrocatalysts may be a promising new resource for electrocatalytic water-splitting devices. In this work, transition metal (cobalt)-incorporated graphitic carbon nitride was synthesized and fabricated in electrodes for use as bifunctional catalysts. The optimum catalytic activity of this bifunctional material for the hydrogen evolution reaction (HER), which benefitted at a cobalt content of 10.6 wt%, was promoted by the highest surface area and conductivity. The activity achieved a minimum overpotential of ~85 mV at 10 mA/cm2 and a Tafel slope of 44.2 mV/dec in an acidic electrolyte. These values of the HER were close to those of a benchmark catalyst (platinum on carbon paper electrode). Moreover, the kinetics evaluation at the optimum catalyst ensured the catalyst flows (Volmer–Heyrovsky mechanism), indicating that the adsorption step is rate-determining for the HER. The activity for the oxygen evolution reaction (OER) indicated an overpotential of ~530 mV at 10 mAcm−2 and a Tafel slope of 193.3 mV/dec, which were slightly less or nearly the same as those of the benchmark catalyst. Stability tests using long-term potential cycles confirmed the high durability of the catalyst for both HER and OER. Moreover, the optimal bifunctional catalyst achieved a current density of 10 mAcm−2 at a cell voltage of 1.84 V, which was slightly less than that of the benchmark catalyst (1.98 V). Thus, this research reveals that the present bifunctional, non-noble metallic electrocatalyst is adequate for use as a water-splitting technology in acidic media. [ABSTRACT FROM AUTHOR]

Anderson-type ([XM6O24]n−) polyoxometalates (POMs) are a class of polymetallic-oxygen cluster inorganic compounds with special structures and properties. They have been paid extensive attention by researchers now, due to their chemical modification and designability, which have been widely applied in the fields of materials, catalysis and medicine. In contemporary years, the application of Anderson-type POMs in catalytic organic oxidation reaction has gradually shown great significance for the research of green catalytic process. In this paper, we investigate the application of Anderson-type POMs in organic synthesis reaction, and these works are summarized according to the different structure of POMs. This will provide a new strategy for further investigation of the catalytic application of Anderson-type POMs and the study of green catalysis. [ABSTRACT FROM AUTHOR]

The development of the future French and European bioeconomies will involve developing new green chemical processes in which catalytic transformations are key. The VAALBIO team (valorization of alkanes and biomass) of the UCCS laboratory (Unité de Catalyse et Chimie du Solide) are working on various catalytic processes, either developing new catalysts and/or designing the whole catalytic processes. Our research is focused on both the fundamental and applied aspects of the processes. Through this review paper, we demonstrate the main topics developed by our team focusing mostly on oxygen- and hydrogen-related processes as well as on green hydrogen production and hybrid catalysis. The social impacts of the bioeconomy are also discussed applying the concept of the institutional compass. [ABSTRACT FROM AUTHOR]

The incorporation of dehydroamino acid or fragments of oxazole into peptide chain is accompanied by a distorted three-dimensional structure and additionally enables the introduction of non-typical side-chain substituents. Thus, such compounds could be building blocks for obtaining novel foldamers and/or artificial enzymes (artzymes). In this paper, effective synthetic procedures leading to such building blocks—tetrapeptides containing glycyldehydroalanine, glycyldehydrophenylalanine, and glycyloxazole subunits—are described. Peptides containing serine were used as substrates for their conversion into peptides containing dehydroalanine and aminomethyloxazole-4-carboxylic acid while considering possible requirements for the introduction of these fragments into long-chain peptides at the last steps of synthesis. [ABSTRACT FROM AUTHOR]

The development of green and sustainable materials for use as heterogeneous catalysts is a growing area of research in chemistry. In this paper, mesoporous SiO2-Al2O3 mixed oxide catalysts with different Si/Al ratios were prepared via hydrolytic (HSG) and nonhydrolytic sol-gel (NHSG) processes. The HSG route was explored in acidic and basic media, while NHSG was investigated in the presence of diisopropylether as an oxygen donor. The obtained materials were characterized using EDX, N2-physisorption, powder XRD, 29Si, 27Al MAS-NMR, and NH3-TPD. This approach offered good control of composition and the Si/Al ratio was found to influence both the texture and the acidity of the mesoporous materials. According to 27Al and 29Si MAS NMR analyses, silicon and aluminum were more regularly distributed in NHSG samples that were also more acidic. Silica–alumina catalysts prepared via NHSG were more active in esterification of acetic acid with n-BuOH. [ABSTRACT FROM AUTHOR]

An electrocatalyst with high oxygen reduction reaction (ORR) activity and high stability during start–stop operation is necessary. In this paper, hollow-structure Pt-Ni electrocatalysts are investigated as ORR catalysts. After synthesis via sacrificial SiO2 template method, the electrocatalyst exhibits much higher specific activity (1.88 mA/cm2) than a commercial Pt/C catalyst. The mass activity (0.49 A/mg) is 7 times higher than the commercial Pt/C catalyst. The kinetics of the ORR is evaluated using Tafel and K-L plots. It also exhibits a higher durability than commercial Pt/C catalyst during accelerated durability test (ADT). Moreover, the electrocatalyst shows good resistance against accelerated durability test for start–stop, the specific activity and mass activity drops 34.6% and 40.8%, respectively, far better than the commercial catalyst. [ABSTRACT FROM AUTHOR]

The effect of H2 activation on the performance of CuFeOx catalyst for low-temperature CO oxidation was investigated. The characterizations of XRD, XPS, H2-TPR, O2-TPD, and in situ DRIFTS were employed to establish the relationship between physicochemical property and catalytic activity. The results showed that the CuFeOx catalyst activated with H2 at 100 °C displayed higher performance, which achieved 99.6% CO conversion at 175 °C. In addition, the H2 activation promoted the generation of Fe2+ species, and more oxygen vacancy could be formation with higher concentration of Oα species, which improved the migration rate of oxygen species in the reaction process. Furthermore, the reducibility of the catalyst was enhanced significantly, which increased the low-temperature activity. Moreover, the in situ DRIFTS experiments revealed that the reaction pathway of CO oxidation followed MvK mechanism at low temperature (<175 °C), and both MvK and L-H mechanism was involved at high temperature. The Cu+-CO and carbonate species were the main reactive intermediates, and the H2 activation increased the concentration of Cu+ species and accelerated the decomposition carbonate species, thus improving the catalytic performance effectively. [ABSTRACT FROM AUTHOR]

Specialized chemicals are used for intensifying food production, including boosting meat and crop yields. Among the applied formulations, antibiotics and pesticides pose a severe threat to the natural balance of the ecosystem, as they either contribute to the development of multidrug resistance among pathogens or exhibit ecotoxic and mutagenic actions of a persistent character. Recently, cold atmospheric pressure plasmas (CAPPs) have emerged as promising technologies for degradation of these organic pollutants. CAPP-based technologies show eco-friendliness and potency for the removal of organic pollutants of diverse chemical formulas and different modes of action. For this reason, various types of CAPP-based systems are presented in this review and assessed in terms of their constructions, types of discharges, operating parameters, and efficiencies in the degradation of antibiotics and persistent organic pollutants. Additionally, the key role of reactive oxygen and nitrogen species (RONS) is highlighted. Moreover, optimization of the CAPP operating parameters seems crucial to effectively remove contaminants. Finally, the CAPP-related paths and technologies are further considered in terms of biological and environmental effects associated with the treatments, including changes in antibacterial properties and toxicity of the exposed solutions, as well as the potential of the CAPP-based strategies for limiting the spread of multidrug resistance. [ABSTRACT FROM AUTHOR]

The current study involved the preparation of a number of MnOx/Sep catalysts using the impregnation (MnOx/Sep-I), hydrothermal (MnOx/Sep-H), and precipitation (MnOx/Sep-P) methods. The MnOx/Sep catalysts that were produced were examined for their ability to catalytically oxidize formaldehyde (HCHO). Through the use of several technologies, including N2 adsorption–desorption, XRD, FTIR, TEM, H2-TPR, O2-TPD, CO2-TPD, and XPS, the function of MnOx in HCHO elimination was examined. The MnOx/Sep-H combination was shown to have superior catalytic activities, outstanding cycle stability, and long-term activity. It was also able to perform complete HCHO conversion at 85 °C with a high GHSV of 6000 mL/(g·h) and 50% humidity. Large specific surface area and pore size, a widely dispersed active component, a high percentage of Mn3+ species, and lattice oxygen concentration all suggested a potential reaction route for HCHO oxidation. This research produced a low-cost, highly effective catalyst for HCHO purification in indoor or industrial air environments. [ABSTRACT FROM AUTHOR]

Ni-based catalysts have been widely used for the CO2 reforming of methane (CRM) process, but deactivation is their main problem. This study created an alternative electronic Ni-NiO-CeO2 interaction on the surface of 5 wt% Ni-5 wt% CeO2/Al2O3-MgO (5Ni5Ce(xh)/MA) catalysts to enhance catalytic potential simultaneously with coke resistance for the CRM process. The Ni-NiO-CeO2 network was developed on Al2O3-MgO through layered double hydroxide synthesis via our ammonia vapor diffusion impregnation method. The physical properties of the fresh catalysts were analyzed employing FESEM, N2 physisorption, and XRD. The chemical properties on the catalyst surface were analyzed employing H2-TPR, XPS, H2-TPD, CO2-TPD, and O2-TPD. The CRM performances of reduced catalysts were evaluated at 600 °C under ambient pressure. Carbon deposits on spent catalysts were determined quantitatively and qualitatively by TPO, FESEM, and XRD. Compared to 5 wt% Ni-5 wt% CeO2/Al2O3-MgO prepared by the traditional impregnation method, the electronic interaction of the Ni-NiO-CeO2 network with the Al2O3-MgO support was constructed along the time of ammonia diffusion treatment. The electronic interaction in the Ni-NiO-CeO2 nanostructure of the treated catalyst develops surface hydroxyl sites with an efficient pathway of OH* and O* transfer that improves catalytic activities and coke oxidation. [ABSTRACT FROM AUTHOR]

The direct hydrogenation of greenhouse gas CO2 to higher alcohols (C2+OH) provides a new route for the production of high-value chemicals. Due to the difficulty of C-C coupling, the formation of higher alcohols is more difficult compared to that of other compounds. In this review, we summarize recent advances in the development of multifunctional catalysts, including noble metal catalysts, Co-based catalysts, Cu-based catalysts, Fe-based catalysts, and tandem catalysts for the direct hydrogenation of CO2 to higher alcohols. Possible reaction mechanisms are discussed based on the structure–activity relationship of the catalysts. The reaction-coupling strategy holds great potential to regulate the reaction network. The effects of the reaction conditions on CO2 hydrogenation are also analyzed. Finally, we discuss the challenges and potential opportunities for the further development of direct CO2 hydrogenation to higher alcohols. [ABSTRACT FROM AUTHOR]

The study aimed to utilize MoO3 catalysts, produced on a pilot scale via combustion reaction, to produce biodiesel from residual oil. Optimization of the process was conducted using a 23 experimental design. Structural characterization of the catalysts was performed through X-ray diffraction, fluorescence, Raman spectroscopy, and particle size distribution analyses. At the same time, thermal properties were examined via thermogravimetry and differential thermal analysis. Catalytic performance was assessed following process optimization. α-MoO3 exhibited a monophasic structure with orthorhombic phase, whereas α/h-MoO3 showed a biphasic structure. α-MoO3 had a larger crystallite size and higher crystallinity, with thermal stability observed up to certain temperatures. X-ray fluorescence confirmed molybdenum oxide predominance in the catalysts, with traces of iron oxide. Particle size distribution analyses revealed polymodal distributions attributed to structural differences. Both catalysts demonstrated activity under all conditions tested, with ester conversions ranging from 93% to 99%. The single-phase catalyst had a long life cycle and was reusable for six biodiesel production cycles. The experimental design proved to be predictive and significant, with the type of catalyst being the most influential variable. Optimal conditions included α-MoO3 catalyst, oil/alcohol ratio of 1/15, and a reaction time of 60 min, resulting in high biodiesel conversion rates and showcasing the viability of MoO3 catalysts in residual oil biodiesel production. [ABSTRACT FROM AUTHOR]

Bioremediation uses the degradation abilities of microorganisms and other organisms to remove harmful pollutants that pollute the natural environment, helping return it to a natural state that is free of harmful substances. Organism-derived enzymes can degrade and eliminate a variety of pollutants and transform them into non-toxic forms; as such, they are expected to be used in bioremediation. However, since enzymes are proteins, the low operational stability and catalytic efficiency of free enzyme-based degradation systems need improvement. Enzyme immobilization methods are often used to overcome these challenges. Several enzyme immobilization methods have been applied to improve operational stability and reduce remediation costs. Herein, we review recent advancements in immobilized enzymes for bioremediation and summarize the methods for preparing immobilized enzymes for use as catalysts and in pollutant degradation systems. Additionally, the advantages, limitations, and future perspectives of immobilized enzymes in bioremediation are discussed. [ABSTRACT FROM AUTHOR]

A series of boron-promoted Ni-Co/Ca catalysts were synthesized by the sol–gel method to enhance syngas generation from biomass pyrolysis. The efficiency of these catalysts was evaluated during the pyrolysis of rice straw in a fixed-bed reactor, varying the Ni/Co ratio, boron addition, calcination temperature, and residence time. The catalysts underwent comprehensive characterization using X-ray diffraction (XRD), Brunauer–Emmett–Teller (BET) analysis, scanning electron microscopy (SEM), and hydrogen temperature-programmed reduction (H2-TPR). The results indicated that the Ni-Co/Ca catalysts yielded superior syngas compared to singular Ni or Co catalysts, suggesting a synergistic interplay between nickel and cobalt. The incorporation of 4% boron significantly decreased the particle size of the active metals, enhancing both the catalytic activity and stability. Optimal syngas production was achieved under the following conditions: a biomass-to-catalyst mass ratio of 2:1, a Ni-Co ratio of 1:1, a calcination temperature of 400 °C, a pyrolysis temperature of 800 °C, and a 20 min residence time. These conditions led to a syngas yield of 431.8 mL/g, a 131.28% increase over the non-catalytic pyrolysis yield of 188.6 mL/g. This study not only demonstrates the potential of Ni-Co/Ca catalysts in biomass pyrolysis for syngas production but also provides a foundation for future catalyst performance optimization. [ABSTRACT FROM AUTHOR]

As an azo dye, OG has toxic and harmful effects on ecosystems. Therefore, there is an urgent need to develop a green, environmentally friendly, and efficient catalyst to activate peroxymonosulfate (PMS) for the degradation of OG. In this study, the catalysts MIL-101(Fe) and NH2-MIL-101(Fe) were prepared using a solvothermal method to carry out degradation experiments. They were characterized by means of XRD, SEM, XPS, and FT-IR, and the results showed that the catalysts were successfully prepared. Then, a catalyst/PMS system was constructed, and the effects of different reaction systems, initial pH, temperature, catalyst dosing, PMS concentration, and the anion effect on the degradation of OG were investigated. Under specific conditions (100 mL OG solution with a concentration of 50 mg/L, pH = 7.3, temperature = 25 °C, 1 mL PMS solution with a concentration of 100 mmol/L, and a catalyst dosage of 0.02 g), the degradation of OG with MIL-101(Fe) was only 36.6% within 60 min; as a comparison, NH2-MIL-101(Fe) could reach up to 97.9%, with a reaction constant k value of 0.07245 min−1. The NH2-MIL-101 (Fe)/PMS reaction system was able to achieve efficient degradation of OG at different pH values (pH = 3~9). The degradation mechanism was analyzed using free-radical quenching tests. The free-radical quenching tests showed that SO4•−, •OH, and 1O2 were the main active species during the degradation of OG. [ABSTRACT FROM AUTHOR]

As traditional fossil fuel energy development faces significant challenges, two-dimensional layered materials have become increasingly popular in various fields and have generated widespread research interest. MXene is an exceptional catalytic material that is typically integrated into functional composite materials with other substances to enhance its catalytic-reaction performance. Improving the thermal stability, electrical conductivity, and electrochemical activity, as well as enhancing the specific surface structure, can make the material an excellent catalyst for photoelectrocatalysis and energy-regeneration reactions. The article mainly outlines the structural characteristics, preparation methods, and applications of MXene in the field of catalysis. This text highlights the latest progress and performance comparison of MXene-based catalytic functional materials in various fields such as electrochemical conversion, photocatalysis, renewable energy, energy storage, and carbon capture and conversion. It also proposes future prospects and discusses the current bottlenecks and challenges in the development of MXene-based catalytic materials. [ABSTRACT FROM AUTHOR]

The 1,4-benzodiazepine structural framework is a fascinating element commonly found in biologically active and pharmaceutically relevant compounds. A highly efficient method for synthesizing 1,4-benzodiazepin-3-ones is described, involving a [4+3]-cycloaddition reaction between 2-amino-β-nitrostyrenes and α-bromohydroxamate, with Cs2CO3 used as a base. This process yielded the desired 1,4-benzodiazepines in good yields. Furthermore, an organocatalytic asymmetric [4+3]-cycloaddition was successfully accomplished using a bifunctional squaramide-based catalyst. This approach enabled the enantioselective synthesis of chiral 1,4-benzodiazepines with commendable yields and moderate enantioselectivities, reaching up to 80% yield and 72% ee. [ABSTRACT FROM AUTHOR]

Stable palladium (II) complexes, incorporating a double (N-benzoylthiourea) arrangement bonded to a complex heterocyclic scaffold, are used as precursors of catalytic species able to promote Suzuki–Miyaura, Mizoroki–Heck, Hiyama, Buchwald–Hartwig, Hirao and Sonogashira–Hagihara cross-coupling transformations in water. These sustainable processes are chemoselective and very versatile. The nanoparticles responsible for these catalytic reactions were analyzed and studied. Their usefulness is demonstrated after several tests and analyses. The heterogeneous character of this species in water was also confirmed. [ABSTRACT FROM AUTHOR]

Since the discovery of classical chiral oxazoline ferrocene ligands in 1995, they have become pivotal in transition metal-catalyzed asymmetric transformations. Over the past decade, a notable evolution has been observed with the emergence of siloxane-substituted oxazoline ferrocenes, demonstrating significant potential as chiral ligands and catalysts. These compounds have consistently delivered exceptional results in diverse and mechanistically distinct transformations, surpassing the capabilities of classical oxazoline ferrocene ligands. This review meticulously delineates the research progress on siloxane-substituted oxazoline ferrocene compounds. It encompasses the synthesis of crucial precursors and desired products, highlights their achievements in asymmetric catalysis reactions, and delves into the exploration of the derivatization of these compounds, emphasizing the introduction of ionophilic groups and their impact on the recovery of transition metal catalysts. In addition to presenting the current state of knowledge, this review propels future research directions by identifying potential topics for further investigation concerning the siloxane-tagged derivatives. These derivatives are poised to be promising candidates for the next generation of highly efficient ligands and catalysts. [ABSTRACT FROM AUTHOR]

The efficiency and performance of proton exchange membrane fuel cells (PEMFCs) are primarily influenced by ORR electrocatalysts. In recent years, atomically dispersed metal–nitrogen–carbon (M-N-C) catalysts have gained significant attention due to their high active center density, high atomic utilization, and high activity. These catalysts are now considered the preferred alternative to traditional noble metal electrocatalysts. The unique properties of M-N-C catalysts are anticipated to enhance the energy conversion efficiency and lower the manufacturing cost of the entire system, thereby facilitating the commercialization and widespread application of fuel cell technology. This article initially delves into the origin of performance and degradation mechanisms of Fe-N-C catalysts from both experimental and theoretical perspectives. Building on this foundation, the focus shifts to strategies aimed at enhancing the activity and durability of atomically dispersed Fe-N-C catalysts. These strategies encompass the use of bimetallic atoms, atomic clusters, heteroatoms (B, S, and P), and morphology regulation to optimize catalytic active sites. This article concludes by detailing the current challenges and future prospects of atomically dispersed Fe-N-C catalysts. [ABSTRACT FROM AUTHOR]

A new tridentate Cu2+ complex based on (E)-1-(pyridin-2-yl)-N-(quinolin-8-yl)methanimine (PQM) was generated and characterized to support the activation of diazo compounds for the formation of new C–N bonds. This neutral Schiff base ligand was structurally characterized to coordinate with copper(II) in an equatorial fashion, yielding a distorted octahedral complex. Upon characterization, this copper(II) complex was used to catalyze an efficient and cost-effective protocol for C–N bond formation between N-nucleophiles and copper carbene complexes arising from the activation of diazo carbonyl compounds. A substrate scope of approximately 15 different amine-based substrates was screened, yielding 2° or 3° amine products with acceptable to good yields under mild reaction conditions. Reactivity towards phenol and thiophenol were also screened, showing relatively weak C–O or C–S bond formation under optimized conditions. [ABSTRACT FROM AUTHOR]

A sulfonyl-chloride-modified lignin-based porous carbon-supported metal phthalocyanine catalyst was prepared and used to replace the traditional Fenton's reagent for lignin degradation. The catalyst underwent a detailed characterization analysis in terms of functional group distributions, surface area, morphological structure, via FT-IR, XPS, BET, and SEM. The catalyst possessed a specific surface area of 638.98 m2/g and a pore volume of 0.291 cm3/g. The prepared catalyst was studied for its ability of oxidative degradation of lignin under different reaction conditions. By optimizing the reaction conditions, a maximum liquid product yield of 38.94% was obtained at 135 °C with 3.5 wt% of catalyst and 15 × 10−2 mol/L H2O2; at the same time, a maximum phenols selectivity of 32.58% was achieved. The compositions and properties of liquid products obtained from lignin degradation using different catalyst concentrations were studied comparatively via GC-MS, FT-IR, 1H-NMR, and EA. Furthermore, the structure changes of solid residues are also discussed. [ABSTRACT FROM AUTHOR]

Efficient and inexpensive electrocatalysts play an important role in the hydrogen evolution reaction (HER) of electrolytic water splitting. Herein, Ni2P-MoC/coal-based carbon fiber (Ni2P-MoC/C-CF) self-supporting catalysts were obtained by low-temperature phosphorization and high-temperature carbonization. The Mo source and oxidized coal were uniformly dispersed in the carbon support by electrospinning technology. A precursor of Ni was introduced by the impregnation method. The synergistic effect of MoC and Ni2P may reduce the strong hydrogen adsorption capacity of pure MoC and provide a fast hydrogen release process. In addition, the C-CFs prepared by electrospinning can not only prevent the agglomeration of MoC and Ni2P particles at a high temperature but also provide a self-supporting support for the catalyst. As a result, the catalytic performance of the HER was improved greatly, and a low overpotential of 112 mV at 10 mA cm−2 was exhibited stably by the Ni2P-MoC/C-CFs. This work not only converts coal into coal-based carbon materials but also provides a feasible pathway for the rational design of large-scale molded hydrogen electrocatalysts. [ABSTRACT FROM AUTHOR]

This study explores an eco-friendly method for recovering platinum group metals from a synthetic automotive three-way catalyst (TWC). Bioleaching of palladium (Pd) using the thiosulfate-copper-ammonia leaching processes, with biogenic thiosulfate sourced from a bioreactor used for biogas biodesulfurization, is proposed as a sustainable alternative to conventional methods. Biogenic thiosulfate production was optimized in a gas-lift bioreactor by studying the pH (8–10) and operation modes (batch and continuous) under anoxic and microaerobic conditions for 35 d. The maximum concentration of 4.9 g S2O32− L−1 of biogenic thiosulfate was reached under optimal conditions (batch mode, pH = 10, and airflow rate 0.033 vvm). To optimize Pd bioleaching from a ground TWC, screening through a Plackett–Burman design determined that oxygen and temperature significantly affected the leaching yield negatively and positively, respectively. Based on these results, an optimization through an experimental design was performed, indicating the optimal conditions to be Na2S2O3 1.2 M, CuSO4 0.03 M, (NH4)2SO4 1.5 M, Na2SO3 0.2 M, pH 8, and 60 °C. A remarkable 96.2 and 93.2% of the total Pd was successfully extracted from the solid at 5% pulp density using both commercially available and biogenic thiosulfate, highlighting the method's versatility for Pd bioleaching from both thiosulfate sources. [ABSTRACT FROM AUTHOR]

Polychlorinated dibenzofurans (PCDFs) are persistent toxic compounds that are ubiquitous in the environment. Nanocomposites of titanium(IV) oxide-vanadium(III) oxide ( Ti 3 V 2 O 7 ) and titanium(IV) oxide-silicon dioxide ( Ti 2 Si 7 O 30 ) were prepared and spectroscopically analyzed as potential decontaminants for dioxin-like materials. The analysis confirmed a homogeneous morphology with nanoscale particle size. The Ti-Si sample was found to have a high surface area compared to the Ti-V composite. Vanadium(III) oxide (V2O5) and silicon dioxide (SiO2) were chosen as materials for the formation of heterogeneous compounds with titanium(IV) oxide (TiO2) because they possess a suitable band alignment with TiO2, thus forming effective photocatalysts. This study evaluated the photodegradation of 2,3,7,8-tetrachlorodibenzo-furan (TCDF) in the presence of Ti-Si and Ti-V oxide composites, which was tested using high- (254 nm) and midenergy (302 nm) UV irradiation sources. While Ti-Si showed success in the photodegradation of 2,3,7,8-TCDF dissolved in a (1:1) methanol–tetrahydrofuran (MeOH-THF) solution, the Ti-V composite proved to be a powerful material in adsorbing TCDF with a high capacity immediately upon mixing. Ti-Si oxide was found to decompose TCDF under the two irradiation sources with 98–99% degradation occurring after 70 min. The use of 254 nm as an irradiation source in the presence of Ti-Si was 4.3 times faster than the analogue reaction irradiated without a catalyst. Byproducts of the degradation were evaluated using gas chromatography–mass spectrometry (GC–MS), resulting in a lower chlorinated congener and less toxicity, as the main degradation product. [ABSTRACT FROM AUTHOR]

Replacing expensive platinum oxygen reduction reaction (ORR) catalysts with atomically dispersed single-atom catalysts is an effective way to improve the energy conversion efficiency of fuel cells. Herein, a series of single-atom catalysts, TM-N2O2Cx (TM=Sc-Zn) with TM-N2O2 active units, were designed, and their catalytic performance for electrocatalytic O2 reduction was investigated based on density functional theory. The results show that TM-N2O2Cx exhibits excellent catalytic activity and stability in acidic media. The eight catalysts (TM=Sc, Ti, V, Cr, Mn, Fe, Co, and Ni) are all 4e− reaction paths, among which Sc-N2O2Cx, Ti-N2O2Cx, and V-N2O2Cx follow dissociative mechanisms and the rest are consistent with associative mechanisms. In particular, Co-N2O2Cx and Ni-N2O2Cx enable a smooth reduction in O2 at small overpotentials (0.44 V and 0.49 V, respectively). Furthermore, a linear relationship between the adsorption free energies of the ORR oxygen-containing intermediates was evident, leading to the development of a volcano plot for the purpose of screening exceptional catalysts for ORR. This research will offer a novel strategy for the design and fabrication of exceptionally efficient non-precious metal catalysts on an atomic scale. [ABSTRACT FROM AUTHOR]

Wastewater contaminated with antibiotics is a major environmental challenge. The oxidation process is one of the most common and effective ways to remove these pollutants. The use of metal-free, green, and inexpensive catalysts can be a good alternative to metal-containing photocatalysts in environmental applications. We developed here the green synthesis of bio-graphenes by using natural precursors (Xanthan, Chitosan, Boswellia, Tragacanth). The use of these precursors can act as templates to create 3D doped graphene structures with special morphology. Also, this method is a simple method for in situ synthesis of doped graphenes. The elements present in the natural biopolymers (N) and other elements in the natural composition (P, S) are easily placed in the graphene structure and improve the catalytic activity due to the structural defects, surface charges, increased electron transfers, and high absorption. The results have shown that the hollow cubic Chitosan-derived graphene has shown the best performance due to the doping of N, S, and P. The Boswellia-derived graphene shows the highest surface area but a lower catalytic performance, which indicates the more effective role of doping in the catalytic activity. In this mechanism, O2 dissolved in water absorbs onto the positively charged C adjacent to N dopants to create oxygenated radicals, which enables the degradation of antibiotic molecules. Light irradiation increases the amount of radicals and rate of antibiotic removal. [ABSTRACT FROM AUTHOR]

The influence of the reaction medium on the surface structure and properties of a Ni-based catalyst used for the reductive transformations of O-, N-, and S-containing aromatic substrates under hydrogen transfer conditions has been studied. The catalysts were characterized by XRD, XPS, and IR spectroscopy and TEM methods before and after the reductive reaction. It has been shown that the conversion of 1-benzothiophene causes irreversible poisoning of the catalyst surface with the formation of the Ni2S3 phase, whereas the conversion of naphthalene, 1-benzofuran, and indole does not cause any phase change of the catalyst at 250 °C. However, after the indole conversion, the catalyst surface remains enriched with N-containing compounds, which are evenly distributed over the surface. [ABSTRACT FROM AUTHOR]

Peptides have demonstrated their efficacy as catalysts in asymmetric aldol reactions. But the constraints inherent in chemical synthesis have imposed limitations on the viability of long-chain peptide catalysts. A noticeable dearth of tools has impeded the swift and effective screening of peptide catalysts using biological methods. To address this, we introduce a straightforward bioprocess for the screening of peptide catalysts for asymmetric aldol reactions. We synthesized several peptides through this method and obtained a 15-amino acid peptide. This peptide exhibited asymmetric aldol catalytic activity, achieving 77% ee in DMSO solvent and 63% ee with over an 80.8% yield in DMSO mixed with a pH 9.0 buffer solution. The successful application of our innovative approach not only represents an advancement but also paves the way for currently unexplored research avenues. [ABSTRACT FROM AUTHOR]

Soot formation is an inevitable consequence of the combustion of carbonaceous fuels in environments rich in reducing agents. Efficient management of pollution in various contexts, such as industrial fires, vehicle engines, and similar applications, relies heavily on the subsequent oxidation of soot particles. Among the oxidizing agents employed for this purpose, oxygen, carbon dioxide, water vapor, and nitrogen dioxide have all demonstrated effectiveness. The scientific framework of this research can be elucidated through the following key aspects: (i) This review situates itself within the broader context of pollution management, emphasizing the importance of effective soot oxidation in reducing emissions and mitigating environmental impacts. (ii) The central research question of this study pertains to the identification and evaluation of catalysts for soot oxidation, with a specific emphasis on ceria-based catalysts. The formulation of this research question arises from the need to enhance our understanding of catalytic mechanisms and their application in environmental remediation. This question serves as the guiding principle that directs the research methodology. (iii) This review seeks to investigate the catalytic mechanisms involved in soot oxidation. (iv) This review highlights the efficacy of ceria-based catalysts as well as other types of catalysts in soot oxidation and elucidate the underlying mechanistic strategies. The significance of these findings is discussed in the context of pollution management and environmental sustainability. This study contributes to the advancement of knowledge in the field of catalysis and provides valuable insights for the development of effective strategies to combat air pollution, ultimately promoting a cleaner and healthier environment. [ABSTRACT FROM AUTHOR]

The development of low platinum loading hydrogen evolution reaction (HER) catalysts with high activity and stability is of great significance to the practical application of hydrogen energy. This paper reports a simple method to synthesize a highly efficient HER catalyst through coating a highly dispersed PtNi alloy on porous nitrogen-doped carbon (MNC) derived from the zeolite imidazolate skeleton. The catalyst is characterized and analyzed by physical characterization methods, such as XRD, SEM, TEM, BET, XPS, and LSV, EIS, it, v-t, etc. The optimized sample exhibits an overpotential of only 26 mV at a current density of 10 mA cm−2, outperforming commercial 20 wt% Pt/C (33 mV). The synthesized catalyst shows a relatively fast HER kinetics as evidenced by the small Tafel slope of 21.5 mV dec−1 due to the small charge transfer resistance, the alloying effect between Pt and Ni, and the interaction between PtNi alloy and carrier. [ABSTRACT FROM AUTHOR]

Water electrolysis to obtain hydrogen in combination with intermittent renewable energy resources is an emerging sustainable alternative to fossil fuels. Among the available electrolyzer technologies, anion exchange membrane water electrolysis (AEMWE) has been paid much attention because of its advantageous behavior compared to other more traditional approaches such as solid oxide electrolyzer cells, and alkaline or proton exchange membrane water electrolyzers. Recently, very promising results have been obtained in the AEMWE technology. This review paper is focused on recent advances in membrane electrode assembly components, paying particular attention to the preparation methods for catalyst coated on gas diffusion layers, which has not been previously reported in the literature for this type of electrolyzers. The most successful methodologies utilized for the preparation of catalysts, including co-precipitation, electrodeposition, sol–gel, hydrothermal, chemical vapor deposition, atomic layer deposition, ion beam sputtering, and magnetron sputtering deposition techniques, have been detailed. Besides a description of these procedures, in this review, we also present a critical appraisal of the efficiency of the water electrolysis carried out with cells fitted with electrodes prepared with these procedures. Based on this analysis, a critical comparison of cell performance is carried out, and future prospects and expected developments of the AEMWE are discussed. [ABSTRACT FROM AUTHOR]

Neopentyl glycol (NPG) is a precursor for the manufacture of many valuable products of industrial importance such as polyester, polyurethane and alkyd resins, synthetic lubricants, hydraulic fluids, drugs, etc. The structure of NPG provides the resins with excellent hydrolytic stability, resistance to weather conditions, good flexibility-hardness balance, and outstanding functional properties. The paper presents a literature review on the development of methods for NPG preparation, focusing primarily on the synthesis of NPG by hydrogenation of hydroxypivaldehyde, which is obtained by the crossed aldol condensation of isobutyraldehyde and formaldehyde. Preparation of the substrates, catalysts, technical and apparatus solutions, and NPG purification were discussed. [ABSTRACT FROM AUTHOR]

The importance of organoselenium compounds has been increasing in synthetic chemistry. These reagents are well-known as electrophiles and nucleophiles in many organic transformations, and in recent years, their functionality as catalysts has also been largely explored. The interest in organoselenium-based catalysts is due to their high efficacy, mild reaction conditions, strong functional compatibility, and great selectivity. Allied to organoselenium catalysts, the use of inorganic and organic oxidants that act by regenerating the catalytic species for the reaction pathway is common. Here, we provide a comprehensive review of the last five years of organic transformations promoted by diorganyl diselenide as a selenium-based catalyst. This report is divided into four sections: (1) cyclisation reactions, (2) addition reactions and oxidative functionalisation, (3) oxidation and reduction reactions, and (4) reactions involving phosphorus-containing starting materials. [ABSTRACT FROM AUTHOR]

This study focuses on the catalytic properties of ruthenium catalysts supported on modified silicalite-1 (with an MFI structure). By post-synthesis modification of silicalite-1 with solutions of alkali metal compound, a novel and cost-effective method was discovered to create basic centers on the surface of silicalite-1 supports. The modification not only affected the basicity of the supports but also their porosity. The influence of the type of alkali solution (KOH or NaOH) and its concentration (0.1 M or 1.0 M) on both the basicity and porosity was investigated. The modified silicalite-1 materials were employed as supports for ruthenium catalysts (1 wt.% Ru) and evaluated for their CO2 methanation activity. The results were compared with the hydrogenation performance of ruthenium catalysts supported on unmodified silicalite-1. Characterization of the supports and catalysts was conducted using techniques such as BET, XRD, FT-IR, ICP-OES, TPR-H2, H2 chemisorption, TPD-CO2, SEM, and TEM. Remarkably, the catalytic activity of ruthenium supported on silicalite-1 treated with 1.0 M NaOH (exhibiting selectivity toward methane above 90% in a reaction temperature range of 250–450 °C) outperformed both unmodified and KOH-modified silicalite-1 supported Ru catalysts. [ABSTRACT FROM AUTHOR]

The process of Fischer–Tropsch synthesis is commonly described as a series of reactions in which CO and H2 are dissociated and adsorbed on the metals and then rearranged to produce hydrocarbons and H2O. However, CO dissociation adsorption is regarded as the initial stage of Fischer–Tropsch synthesis and an essential factor in the control of catalytic activity. Several pathways have been proposed to activate CO, namely direct CO dissociation, activation hydrogenation, and activation by insertion into growing chains. In addition, H2O is considered an important by-product of Fischer–Tropsch synthesis reactions and has been shown to play a key role in regulating the distribution of Fischer–Tropsch synthesis products. The presence of H2O may influence the reaction rate, the product distribution, and the deactivation rate. Focus on H2O molecules and H2O-derivatives (H*, OH* and O*) can assist CO activation hydrogenation on Fe- and Co-based catalysts. In this work, the intermediates (C*, O*, HCO*, COH*, COH*, CH*, etc.) and reaction pathways were analyzed, and the H2O and H2O derivatives (H*, OH* and O*) on Fe- and Co-based catalysts and their role in the Fischer–Tropsch synthesis reaction process were reviewed. [ABSTRACT FROM AUTHOR]

Biomass as a renewable energy resource is a major topic on a global scale. Several types of biomass heat treatment methods have been introduced to obtain useful byproducts via pyrolysis. Microwaves are a practical replacement for conventional stoves and ovens to perform pyrolysis of biomass. Their rapid heating rate and user-friendliness make them a good choice for the pyrolysis process over conventional methods. The current study reviewed research articles that used microwaves for the pyrolysis process on different types of biomass. This study primarily provides comprehensive details about the pyrolysis process, especially microwave-assisted pyrolysis (MAP) and its feasibility for treating biomass. A systematic literature review, according to the PRISMA guidelines, was performed to find research articles on biomass treatment using MAP technology. We analyzed various research studies (n = 32), retrieved from different databases, that used MAP for pyrolysis on various types of biomass, and we achieved good results. The main goal of this study was to examine the usefulness of the MAP technique, comparing its effects on distinguished types of biomass. We found MAP's effective parameters, namely, temperature, concentration of microwave absorber, moisture percentage of starting material and flow rate, microwave power and residence time of the initial sweep gas that control the pyrolysis process, and effect quality of byproducts. The catalytic agent in MAP pyrolysis was found to be useful for treating biomass, and that it has great potential to increase (nearly double) the production yield. Although MAP could not be used for all types of materials due to some challenges, it produced good results compared to conventional heating (pyrolysis) methods. We concluded that MAP is an effective method for reducing pyrolysis reaction time and improving the quality of value-added products. Also, MAP eliminates the shredding requirement for biomass and improves heating quality. Therefore, it is a viable method for reducing pyrolysis processing costs and should be applied on a larger scale than lab scale for commercialization. [ABSTRACT FROM AUTHOR]

Supercritical water gasification has emerged as a promising technology to sustainably convert waste residues into clean gaseous fuels rich in combustible gases such as hydrogen and methane. The composition and yield of gases from hydrothermal gasification depend on process conditions such as temperature, pressure, reaction time, feedstock concentration, and reactor geometry. However, catalysts also play a vital role in enhancing the gasification reactions and selectively altering the composition of gas products. Catalysts can also enhance hydrothermal reforming and cracking of biomass to achieve desired gas yields at moderate temperatures, thereby reducing the energy input of the hydrothermal gasification process. However, due to the complex hydrodynamics of supercritical water, the literature is limited regarding the synthesis, application, and performance of catalysts used in hydrothermal gasification. Hence, this review provides a detailed discussion of different heterogeneous catalysts (e.g., metal oxides and transition metals), homogeneous catalysts (e.g., hydroxides and carbonates), and novel carbonaceous catalysts deployed in hydrothermal gasification. The article also summarizes the advantages, disadvantages, and performance of these catalysts in accelerating specific reactions during hydrothermal gasification of biomass, such as water–gas shift, methanation, hydrogenation, reforming, hydrolysis, cracking, bond cleavage, and depolymerization. Different reaction mechanisms involving a variety of catalysts during the hydrothermal gasification of biomass are outlined. The article also highlights recent advancements with recommendations for catalytic supercritical water gasification of biomass and its model compounds, and it evaluates process viability and feasibility for commercialization. [ABSTRACT FROM AUTHOR]

In this paper, the degradation of the diazo dye naphthol blue black (NBB) using the Galvano-Fenton process is studied experimentally and numerically. The simulations are carried out based on the anodic, cathodic, and 34 elementary reactions evolving in the electrolyte, in addition to the oxidative attack of NBB by HO • at a constant rate of 3.35 × 10 7   mol − 1 · m 3 · s − 1 during the initiation stage of the chain reactions. The selection of the operating conditions including the pH of the electrolyte, the stirring speed, and the electrodes disposition is performed by assessing the kinetics of NBB degradation; these parameters are set to 3, 350 rpm and a parallel disposition with a 3 cm inter-electrode distance, respectively. The kinetics of Fe (III) in the electrolyte were monitored using the principles of Fricke dosimetry and simulated numerically. The model showed more than a 96% correlation with the experimental results in both the blank test and the presence of the dye. The effects of H 2 O 2 and NBB concentrations on the degradation of the dye were examined jointly with the evolution of the simulated H 2 O 2 , Fe 2 + , and HO • concentrations in the electrolyte. The model demonstrated a good correlation with the experimental results in terms of the initial degradation rates, with correlation coefficients exceeding 98%. [ABSTRACT FROM AUTHOR]

Ab initio kinetic studies are important to understand and design novel chemical reactions. While the Artificial Force Induced Reaction (AFIR) method provides a convenient and efficient framework for kinetic studies, accurate explorations of reaction path networks incur high computational costs. In this article, we are investigating the applicability of Neural Network Potentials (NNP) to accelerate such studies. For this purpose, we are reporting a novel theoretical study of ethylene hydrogenation with a transition metal complex inspired by Wilkinson's catalyst, using the AFIR method. The resulting reaction path network was analyzed by the Generative Topographic Mapping method. The network's geometries were then used to train a state-of-the-art NNP model, to replace expensive ab initio calculations with fast NNP predictions during the search. This procedure was applied to run the first NNP-powered reaction path network exploration using the AFIR method. We discovered that such explorations are particularly challenging for general purpose NNP models, and we identified the underlying limitations. In addition, we are proposing to overcome these challenges by complementing NNP models with fast semiempirical predictions. The proposed solution offers a generally applicable framework, laying the foundations to further accelerate ab initio kinetic studies with Machine Learning Force Fields, and ultimately explore larger systems that are currently inaccessible. [ABSTRACT FROM AUTHOR]

The development of highly active and low-cost catalysts for use in oxygen reduction reaction (ORR) is crucial to many advanced and eco-friendly energy techniques. N-doped carbons are promising ORR catalysts. However, their performance is still limited. In this work, a zinc-mediated template synthesis strategy for the development of a highly active ORR catalyst with hierarchical porous structures was presented. The optimal catalyst exhibited high ORR performance in a 0.1 M KOH solution, with a half-wave potential of 0.89 V vs. RHE. Additionally, the catalyst exhibited excellent methanol tolerance and stability. After a 20,000 s continuous operation, no obvious performance decay was observed. When used as the air–electrode catalyst in a zinc–air battery (ZAB), it delivered an outstanding discharging performance, with peak power density and specific capacity as high as 196.3 mW cm−2 and 811.5 mAh gZn−1, respectively. Its high performance and stability endow it with potential in practical and commercial applications as a highly active ORR catalyst. Additionally, it is believed that the presented strategy can be applied to the rational design and fabrication of highly active and stable ORR catalysts for use in eco-friendly and future-oriented energy techniques. [ABSTRACT FROM AUTHOR]