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Ce-promoted Ni/Mg/Al mixed oxides hydrotalcite-derived catalyst washcoated on metallic FeCrAlloy monolith was investigated in catalytic steam cracking of Vacuum Gas Oil (VGO) over a mild temperature range (300–400 °C). Hydrotalcite-derived powder solids were used as a slurry for the washcoating process were synthesized using co-precipitation and subsequent thermal decomposition. The as-fabricated catalyst exhibited over 40% VGO conversion with 46% light cut (Naphtha, Kerosene and Diesel) and 47.7% light VGO selectivity and Total Acidity Number of 0.9 mg KOH/g sample. This result seems promising for steam cracking of VGO over a novel structured catalyst. The washcoated catalyst was characterized using X-ray diffraction, surface area and X-ray Photoelectron Spectroscopy. Also, the liquid products composition/ quality and gas products composition were measured with various techniques such as simulation distillation, gas chromatography, viscosimeter and micro carbon residue.

In this research, a new phospholipid based monolith was fabricated by in situ co-polymerization of 1-dodecanoyl-2-(11-methacrylamidoundecanoyl)-sn-glycero-3-phosphoethanolamine (MDSPE) and ethylene dimethacrylate (EDMA) to mimic bio-membrane environment. Excellent physicochemical properties of this novel monolith were achieved, including column efficiency, stability and permeability. Moreover, the biomimetic monolith showed outstanding separation capability for a series of intact proteins and small molecules. In particular, it exhibited good potential as an alternative to the commercial immobilized artificial membrane (IAM) column (IAM.PC.DD2) for studying drug-membrane interactions. This study not only enriched the types of IAM stationary phases, but also provided a simple model for the prediction of phosphatidylethanolamine related properties of drug candidates.

Exfoliated 2D MAX Ti3AlC2 conductive cocatalyst anchored with g-C3N4/TiO2 to construct 2D/0D/2D heterojunction has been explored for enhanced CO2 photoreduction in a fixed-bed and monolith photoreactor. The TiO2 particle sizes (NPs and MPs) were systematically investigated to determine effective metal-support interaction with faster charge carrier separation among the composite materials. When TiO2 NPs were anchored with 2D Ti3AlC2 MAX structure, 10.44 folds higher CH4 production was observed compared to anchoring TiO2 MPs. Maximum CH4 yield rate of 2103.5 µmol g−1 h−1 achieved at selectivity 96.59% using ternary g-C3N4/TiO2/Ti3AlC2 2D/0D/2D composite which is 2.73 and 7.45 folds higher than using binary g-C3N4/Ti3AlC2 MAX and TiO2 NPs/Ti3AlC2 samples, respectively. A step-scheme (S-scheme) photocatalytic mechanism operates in this composite, suppressed the recombination of useful electron and holes and provides higher reduction potential for efficient CO2 conversion to CO and CH4. More importantly, when light intensity was increased by 5 folds, CH4 production rate was increased by 3.59 folds under visible light. The performance of composite catalyst was further investigated in a fixed-bed and monolith photoreactor and found monolithic support increased CO production by 2.64 folds, whereas, 53.99 times lower CH4 production was noticed. The lower photocatalytic activity in a monolith photoreactor was due to lower visible light penetration into the microchannels. Thus, 2D MAX Ti3AlC2 composite catalyst can be constructed for selective photocatalytic CO2 methanation under visible light in a fixed-bed photoreactor.

In this work, we report on fabricating a solid-state naked-eye sensor for targeting industrially relevant cobalt ions, using a tailor-made bimodal macro-/meso-porous polymer carbon-based monolithic cage-like template of high surface area and voluminous porosity. The solid-state sensor has concocted through the homogenous dispersion of a unique chromoionophoric ion-receptor (probe), i.e., 4-((9H-purin-6-yl)diazenyl)-6-hexylbenzene-1,3-diol (PDHBD), onto the polymer monolith. The ion-receptor anchored monolithic sensor's structural and surface morphology features are subjected to characterization by surface area analysis, electron microscopic, diffraction, and spectroscopic techniques. The monolith sensor exhibits exclusive selectivity for Co(II), with an incremental color transition from pale-orange to deep-red, for Co(II) concentrations ranging from 0-500 ppb. The influence of investigational factors is systematically studied to enhance sensor performance. The monolithic sensor reveals a maximum signal response in the pH range of 7.0-8.0, with response kinetics of ≤3 min, at 40°C≤ T ≥20°C, for Co(II). The multi-reusable solid-state sensor exhibits a superior detection and quantification limit of 0.3 and 1.0 ppb, respectively, for Co(II). The sensor proves its real-time monitoring efficiency in recovering Co(II) from environmental and industrial water samples with excellent data reproducibility. The binding mechanism of PDHBD molecules with Co(II) for exclusive ion-selectivity is studied using density functional theory.

In this paper, it was used a monolithic-type structured photoreactor with a high surface area calcined brass as a substrate for TiO2-P25. The TiO2 immobilization over the monoliths was carried out by the washcoating process. The films were characterized via XRD and diffuse reflectance. The monoliths were tested at a recirculation reactor using a solar simulator as an energy source and their efficiency was evaluated at Reactive Black 5 (RB5) textile dye photodegradation. It was investigated the effect of the impregnated catalyst mass, the monolith size, the initial dye concentration and the reaction medium pH. The preliminary tests of the brass calcination temperature (500, 600, and 700 °C) showed the formation of ZnO and CuO semiconductors at the brass surface, thus suggesting that the monoliths can act as photocatalysts. Furthermore, the brass calcined at 500 °C showed the greater formation of both oxides (ZnO and CuO) and greater photocatalytic efficiency. The TiO2/brass monolith presented more than 59 % of degradation for an initial dye concentration of 12.5 mg.L−1. In regarding to stability test, the system set forth a decrease at RB5 degradation efficiency of 62 % and presented an adherence of 77.5 % after 5 cycles of monoliths reuse. Therefore, the brass monolithic systems with immobilized TiO2 showed to be a feasible alternative for textile effluent treatment.

Hierarchically cellular, stiff, and lightweight niobium carbide (NbC)-pyrolytic carbon (PyC) monolithic foam composites possessing excellent electromagnetic interference shielding effectiveness (EMI SE) were developed via a natural wood template-based method. Pyrolytic carbon derived from the decomposed cellulose in the wood worked as the carbon source for the growth of NbC phase, and the NbC-PyC heterogeneous nano-interface formed between the residual PyC and the freshly formed NbC. Multi-loss mechanisms (e.g. conductive loss, dipole polarization loss, and especially interface polarization loss) were established by controlling the NbC content and residual PyC phase in the NbC-PyC foams, which significantly improved the absorption capability. Compared to 28.0 dB of PyC monolith, the EMI SE of NbC-PyC foam can reach 54.8 dB when the thickness is 0.5 mm, which outperforms the other porous-based shielding materials. Due to the highly porous structure of pristine wood, the resulting NbC-PyC foam exhibited a low density of 0.48 g/cm3, which is ~ 1/16 of dense NbC (7.78 g/cm3). Generally, this work introduces innovative ideas for designing novel and advanced transition metal carbide–carbon composite materials.

Structured catalysts have important advantages compared to powder formulations and they are required for processes intensification. In this work, three different ceramic structures: a cordierite monolith, an alumina foam and an alumina-silica paper were used as substrates for the deposition of a NiO-Al2O3 coating and tested in the oxidative dehydrogenation of ethane to produce ethylene. For comparison, a NiO-Al2O3 powder catalyst was also prepared. Nickel oxide species with different physicochemical features were obtained over each structure, evidenced by morphological (SEM-EDX) and physicochemical characterization (XRD, LRS and XPS). The best distributions of the catalytic coatings and NiO physicochemical properties were obtained when the monolith and the foam were used as substrates. These led to higher NiO-Al2O3 interactions and consequently to high ethylene selectivity values, 70–90 %, corresponding to the former an ethane conversion of 22 % and to the latter a 5 %. The distribution of the active phase on the ceramic paper was heterogeneous, with NiO agglomerations and poor NiO-support interaction thus achieving low olefin selectivity (∼ 30 %). The addition of a second element such as cerium was also studied in those structured catalysts with high selectivity, resulting in both cases in an increment of ethane conversion but a decrease in ethylene selectivity. This behavior was attributed to the generation of electrophilic oxygen species.

We use a multi-scale multi-mode reduced order model for coupled homogeneous-catalytic reaction systems to present a comprehensive bifurcation (ignition-extinction) analysis of the oxidative coupling of methane (OCM) in monolith, gauze or wire-mesh type reactors. We determine the impact of methane to oxygen ratio in the feed, space time, channel hydraulic radius (or gas phase to catalyst volume ratio), washcoat diffusional limitations, operating pressure and substrate thermal conductivity on the ignition and extinction behavior of the system as a function of the feed temperature. The computations show that for typical operating conditions, the methane conversion and C 2 product selectivity are non-monotonic on the ignited branch and there exists an optimum point of operation away from the extinction point. The predicted methane, oxygen conversions and C 2 selectivity are compared to reported experimental results in the literature. We also present the various species and temperature profiles along the length of the reactor and examine how these profiles are impacted by the substrate conductivity, space time and heat loss. The results obtained for monolith, gauze or wire-mesh reactors are compared to those in packed-bed reactors and suggestions are provided for scale-up and optimization of these reactors for carrying out OCM as well as other catalytic partial oxidations.

For the design of novel potent molecules against therapeutic protein targets produced in a low quantity or that are very expensive, the development of miniaturized analytical techniques is of crucial importance.

Efficiently processing volatile organic compounds (VOCs) with nonthermal plasma and honeycomb catalyst for practical industrial applications presents a sizable challenge. An attempt has been made to generate a large volume of uniform plasma at atmospheric pressure in a practical-scale honeycomb catalyst. H-ZSM-5, a type of zeolite, was washcoated on a commercial bare honeycomb monolith as the catalyst-supporting material, after which the monolith was impregnated with Pd. The plasma discharge power can be controlled by controlling the humidity in the feed gas, metal content, applied voltage, and total flow rate of the feed gas. The plasma was characterized by the voltage and current waveforms, and optical emission spectroscopy (OES). In this study, 85% of dilute toluene (15 ppm) was successfully removed from an airstream at a large flow rate of 60 L/min with an energy density of 84 J/L. Under this condition, the selectivity of CO2 was 76%. This investigation demonstrated the practical applicability of the plasma-honeycomb catalytic reactor to process a fast-flowing feed gas without resulting in a significant large pressure drop, which can hardly be achieved with typical packed-bed plasma reactors.

Separation of oil/water mixtures using monolithic porous materials is an attractive approach for absorbing a variety of polar and apolar solvents from their mixtures. In our work, we report a simple and low-cost fabrication of macroporous monolith followed by hydrophobization with adsorption of candle soot particles (CSPs). This modification makes it omniphilic and substantially enhance its hydrophobic nature by packing of CSPs into the polymeric walls of the monolith as confirmed by scanning electron micrographs. Water contact angle (WCA) and solvent absorption behaviour of CSP-adsorbed monoliths were studied and subsequently, were employed for the separation of floating oil/water mixture. Unmodified monolith S0 is hydrophilic in nature and absorbs over 30 times its weight when dipped in water. WCA study reveals that the contact angle increases systematically from 0 to ∼ 130° with an increase in CSP concentration and monolith S5 can absorb chloroform more than 38 times its weight. Monoliths possess high mechanical strength and can be used for repetitive compression/absorption cycle for solvent absorption. These high porosity sponges provide an effective strategy, high-performance controllable absorbability, and can be used as a separation tool for floating oil/water mixtures.

Coated monolith/foam catalysts are promising materials for chemistry applications due to structured reactor configuratiions providing low expansion coefficient, good thermal stability and low pressure loss. In this study, powedered Ni(0)/La2O3 catalysts in perovskite structures, were deposited on cordierite monolith substrates (2MgO-2Al2O3-5SiO2) by dip-coating method. The catalysts were characterized by N2 adsorption, XRD, TPR-H2 analysis. The activity of structured catalysts with various powder loadings (4, 8, 12, 20 and 30 wt %) were evaluated in combined Steam-CO2 reforming reaction (CH4/CO2/H2O = 2/1/2 vol%) at GHSV = 60.000 h-1. XRD and TPR results showed that the active phase LaNiO3 were mainly Ni and La2O3distributed on the surface of cordierite channels after air calcination of 850oC, 3 hours and hydrogen reduction of 600oC, 2 hours . The conversion of methane and CO2 on monolith catalysts, with proper active sites loadings of 12 – 20 wt%, were close to 80 vol% at 800oC. At the same reaction amount of active sites, the feedstock conversion on LaNiO3/monolith (12 %wt LaNiO3/monolith) was significantly higher than on corresponding powdered type, respectively 1.6 times of CH4, 1.8 times of CO2 conversion.

The possibility of using a new graphene-based carbon monolith for searching new oil deposits or branches adjacent to the already registered oilfields by areal geochemical survey is demonstrated. The material has been developed at the Faculty of Chemistry of M. V. Lomonosov Moscow State University. Sorption of volatile organic compounds (VOCs) from soil air at the oilfield was carried out using two sorbents (carbon adsorbent and Tenax-TA traditionally used for such analyses) with subsequent determination by gas chromatography with mass spectrometric detection and thermal desorption as a way of sample injection (TD/GC/MS). The new material absorbs more hydrocarbons (n-alkanes and monoaromatics) in the range from C8 to C16 than Tenax-TA, the intensities of the chromatographic peaks of the compounds also being higher. The phenomenon of irreversible sorption from carbon materials is observed for VOCs from C17 and more. However, the concentration of such substances in the soil air is rather low due to the low pressure of saturated vapors of these compounds under normal conditions. Hence, the chromatogram of carbon monolith reflects the macro-characteristics of this oil deposit better than Tenax-TA. To increase the sensitivity of the determination, a preliminary optimization of thermal desorption conditions was carried out. The values of the helium flow rate through the sorbent sample and the desorption time of the compounds are chosen to get the largest peak area. The regeneration of sorbent samples is carried out to provide the possibility of their reusage. Tenax-TA decomposes at lower temperatures compared to carbon sorbent and thus cannot be purified completely unlike the new monolith. The graphene-based sorbent is reusable and much cheaper in the manufacture than imported polymer Tenax-TA since it is made of domestic materials.

We have developed a method for the esterification of carboxylic acids with alcohols using amphipathic, monolithic-resin bearing sulfonic acid moieties as cation exchange functions (monolith-SO3H). ...

In this study, we optimized a polymerization mixture to synthesize poly(acrylamide-co-N,N'-methylenebisacrylamide) monolithic stationary phases for hydrophilic-interaction chromatography (HILIC) of intact proteins. Thermal polymerization was performed, and the effects of varying the amount of cross-linker and the porogen composition on the separation performance of the resulting columns were studied. The homogeneity of the structure and the different porosities were examined through scanning electron microscopy (SEM). Further characterization of the monolithic structure revealed a permeable (Kf between 2.5 × 10-15 and 1.40 × 10-13 m2) and polar stationary phase suitable for HILIC. The HILIC separation performance of the different columns was assessed using gradient separation of a sample containing four intact proteins, with the best performing stationary phase exhibiting a peak capacity of 51 in a gradient of 25 min. Polyacrylamide-based materials were compared with a silica-based particulate amide phase (2.7 μm core-shell particles). The monolith has no residual silanol sites and, therefore, fewer sites for ion-exchange interactions with proteins. Thus, it required lower concentrations of ion-pair reagent in HILIC of intact proteins. When using 0.1% of trifluoroacetic acid (TFA), the peak capacities of the two columns were similar (30 and 34 for the monolithic and packed column, respectively). However, when decreasing the concentration of TFA to 0.005%, the monolithic column maintained similar separation performance and selectivity (peak capacity 23), whereas the packed column showed greatly reduced performance (peak capacity 12), lower selectivity, and inability to elute all four reference proteins. Finally, using a mobile phase containing 0.1% formic acid and 0.005% TFA, the HILIC separation on the monolithic column was successfully hyphenated with high-resolution mass spectrometry. Detection sensitivity for protein and glycoproteins was increased and the amount of adducts formed was decreased in comparison with separations performed at 0.1% TFA.

Sunflower oil hydrogenation was carried out in a 2 mm diameter jacketed capillary reactor coated with a Pd/Al2O3 catalyst, mimicking a channel of a heat exchanger monolith reactor. The operating conditions were chosen to ensure Taylor flow conditions and to evaluate their impact on the reaction selectivity. CFD simulations of the experiments were performed using the unit cell approach. They accounted for the dependence of viscosity on the degree of oil saturation, kinetic laws describing the effects of pressure on cis/trans selectivity, and bubble shrinkage along the channel using a moving mesh strategy. The model captured the experimental trends, in which the fraction of monounsaturated cis fatty acids did not exceed 35% (vs 30% originally). Poor selectivity is mainly due to the strong mass transfer resistance at the catalyst wall, either from fatty acids (favoring their complete saturation) and/or from hydrogen (due to bubble shrinkage, favoring cis to trans isomerization)

Due to the limited specific capacity of graphite anodes in lithium-ion batteries (LIBs), it is imperative to find alternatives with better performance. In this work, we propose, for the first time, a three dimensional (3D) porous metallic 5-5-8 carbon monolith with hexagonal lattice as a potential candidate. With 5-5-8 carbon nanoribbon as the building block, this material, named Hex-C558, goes beyond graphene-nanoribbon-based 3D porous carbon structures. Using first-principles calculations, we show that Hex-C558 is not only dynamically and thermally stable, but also is energetically more favorable than many other theoretically predicted carbon allotropes. More importantly, Hex-C558 is metallic with ordered ionic conducting channels and possesses a low mass density of 1.05 gcm−3, exhibiting great potential for ion-battery applications. As an anode for LIBs, Hex-C558 possesses a large specific capacity of 591 mAhg−1, low diffusion energy barrier of 0.27 eV (at low Li concentration) and 0.52 eV (at high Li concentration), a low open-circuit voltage of 0.51 V, and a small volume change of 2.4%. This work provides a new route for the design and synthesis of novel carbon materials for battery applications by using pentagon-based building units.

An investigation of the effect of catalyst separation in stratified autothermal reforming was conducted. A reactor containing two catalyst beds - a platinum group metal monolith followed by a pelletized copper-based steam reforming catalyst - was investigated under four different configurations corresponding to different distances between the catalyst beds. Heat shields were utilized in some trials to promote reactant mixing and increase radial heat transfer through the reactor. Reactor performance, as measured by conversion, hydrogen yield, and selectivity was quantified for each configuration. Results confirm that the reaction is heat transfer limited, with the short-distance, high-temperature configuration corresponding to an improved reactor performance. This was indicated by a 4–5% drop in methanol conversion as well as in the hydrogen yield and selectivity upon the addition of spacing between the catalysts. Visual inspection of the catalyst revealed suspected signs of potential degradation due to high temperatures, indicating the need for longer-duration experiments to determine the long-term effects of sustained high temperatures on catalyst performance.

The applications of silica aerogels are restricted due to their intrinsic fragile property. Polymerization of di-isocyanates can be templated onto the mesoporous surface of the –NH2 group modified silica clusters, resulting in the conformal crosslinked coating on surface of silica clusters. Aminopropyltriethoxysilane (APTES), as the silica co-precursor and amine group modification agent, is involved containing tetramethyl orthosilicate (TMOS) silica precursor, while hexamethylene diisocyanate (HDI) is incorporated as the polymer crosslinking agent. The effects of different amounts of APTES on the physicochemical properties of the resulting crosslinked aerogels are investigated. The results show that the optimized APTES/TMOS volume ratio can be determined at 0.5:1. The resulting optimal crosslinked silica aerogel possesses large BET specific surface area of 150.9 m2/g, low thermal conductivity of 0.037 W/(m·K), and the Young's modulus is as large as 18 MPa under strain of 4.2%, much higher than that in the previously published works. The polymerization reaction mechanism forming the polyurethane chains has also been proposed. In addition, the interactions between silica clusters and polymer chains are studied by molecular mechanics and molecular dynamics. The interactions are mainly dependent on non-bonding energy, and the electrostatic energy has decisive impact on the combination of silica clusters and polymer chains. The density field of C, H, N, O, and Si elements overlaps with each other, indicating that the polymer crosslinked silica aerogel maintains typical three-dimensional porous structure. The N element enriches in the region between silica clusters, further verifying the formation –CONH–(CH2)6–CONH- polyurethane chains, which is actually responsible for the much enhanced mechanical property.

A stationary phase based on sub-2 μm ground silica monolith particles was fabricated by in situ polymerization and applied in micro-column for separation of peptides. The sub-2 μm silica particles were obtained from monolith using sol-gel process followed by grinding and sedimentation to remove the fines. Initially, the silica monolith particles were pretreated with 3-trimethoxysilyl propyl methacrylate to attach double-bonded ligands onto the surface, then a network structure was formed onto the surface of the particle using styrene, N-isopropylacrylamide, and ethylene glycoldimethacrylate. The effect of the flow rate of the mobile phase on the separation performance was investigated. The stationary phase was characterized by field emission scanning electron microscopy, thermogravimetry, particle size distribution, and element analysis. The resultant phase was packed in glass-lined stainless steel micro-columns (2.1 mm × 50 mm) and evaluated for fast separation. An average number of theoretical plates as high as 9800 plates/column (5.10 μm plate height) was achieved for five synthetic peptides under the optimized flow rate of 0.15 mL/min. The repeatabilities of column-to-column, intraday, and interday through relative standard deviation were found better than 4%, exhibiting satisfactory repeatability of the developed micro-column for fast separation of peptides.

This paper presents the experimental investigation of full-scale precast concrete beam-column connections subjected to cyclic lateral loading. The specimen consists of three models. Two of which are precast beam-column connections and one is monolith. The precast and monolith specimen were designed for the same strength. The cross-sectional dimensions of the beam 250 mm x 300 mm and column 300 mm x 300 mm. Connections are placed in plastic hinge area, with a distance of h (beam height) from the face of the column which is expected to occur first destruction. Precast construction joints are distinguished, with 3 different models, namely monolith, double notch type 1 (STR-1), and double notch type 2 (STR-2). Maximum load capacity, hysterical behavior and energy dissipation are measured, and capacity is compared. The results showed that beam-column joint STR-2 are better able to absorb energy than beam column joint monolith and beam-column joint STR-1. Kumulative energy dissipation of monolith about 9333.07 kN-mm, STR-1 is 8336.76 kN-mm, and STR-2 is 10162.52 kN-mm. The use of dual notch connections (STR-1 and STR-2) provides satisfactory performance, which is marked by meeting the minimum relative energy dissipation ratio at a 3.5% drift according to the ACI Committee 374.1-05. The results show that the STR-2 beam-column connection is more capable of absorbing energy than the monolith beam-column connection and STR-1 beam connection. the value of monolithic cumulative energy dissipation is around 9333.07 kN-mm, STR-1 is 8336.76 kN-mm, and STR-2 is 10162.52 kN-mm. in principle, all three test specimens, monoliths, STR-1 and STR-2 provide satisfactory stability performance under lateral cyclic loads, because they still meet the minimum relative energy dissipation ratio at a deviation of 3.5% according to the ACI Committee 374.1 -05

Selective and durable fixed-bed catalysts are highly desirable for developing eco-efficient HPPO (hydrogen peroxide propylene oxide) process. The powder titanosilicate catalysts must be shaped before being applied in industrial processes. As the essential additives for preparing formed catalysts, binders are usually the catalytically inert components, but they would cover the surface and pore mouth of zeolite, thereby declining the accessibility of active sites. By recrystallizing the binder (silica)/Ti-MWW extrudates with the assistance of dual organic structure-directing agents, the silica binder was converted into MWW zeolite phase to form a structured binder-free Ti-MWW zeolite with Si-rich shell, which enhanced the diffusion efficiency and maintained the mechanical strength. Meanwhile, due to the partial dissolution of Si in the Ti-MWW matrix, abundant silanol nests formed and part of framework TiO4 species were transferred into open TiO6 ones, improving the accumulation and activation ability of H2O2 inside the monolith. Successive piperidine treatment and fluoridation of the binder-free Ti-MWW further enhanced the H2O2 activation and oxygen transfer ability of the active Ti sites, and stabilized the Ti-OOH intermediate through hydrogen bond formed between the end H in Ti-OOH and the adjacent Si-F species, thus achieving a more efficient epoxidation process. Additionally, the side reaction of PO hydrolysis was inhibited because the modification effectively quenched numerous Si-OH groups. The lifetime of the modified binder-free Ti-MWW catalyst was 2400 h with the H2O2 conversion and PO selectivity both above 99.5%.

A carboxy precursor monolithic column, namely poly(carboxy ethyl acrylate-co-ethylene glycol dimethacrylate) was first produced in a 100 μm i.d. fused-silica capillary and subsequently surface bonded with n-octadecyl (C18 ) ligands by a post-polymerization functionalization process with octadecylamine in the presence of N,N´-dicyclohexylcarbodiimide. The bonding of octadecyl ligands was achieved via an amide linkage between the carboxy functions of the precursor monolith and the amino group of the octadecylamine compound. The resulting C18 monolith exhibited a very low electroosmotic flow (EOF), a fact that required the incorporation of small amounts of 2-acrylamido-2-methylpropane sulfonic acid (AMPS) in the polymerization solution to produce a precursor monolith with fixed negative charges of sulfonate groups. This may indicate that the conjugation of the carboxy functions with octadecylamine occurred to a large extent so that the amount of residual carboxy functions was sparsely dispersed and not enough to produce a desirable EOF. The EOF velocity of the C18 column having fixed negative charges provided by the incorporated AMPS increased with increasing ACN content of the mobile phase signaling an increased binding of mobile phase ions to the polar amide linkages near the monolithic surface, and a decreased viscosity of the mobile phase, both of which would result in increased EOF velocity. The C18 monolithic column constituted a novel nonpolar sorbent for reversed-phase capillary electrochromatography for nonpolar solutes, e.g., alkylbenzenes, alkylphenyl ketones, and polyaromatic hydrocarbons, and slightly polar compounds including phenol and chlorophenols. The C18 monolithic column exhibited relatively high selectivity toward chlorophenols differing by one chloro substituent.

Solar-powered atmospheric water harvest (SAWH) with metal-organic frameworks (MOFs) represents one of the most sustainable, energy-efficient, and low-cost ways to alleviate water shortage stress in arid regions. However, the daily water productivity of previously developed SAWH devices remains low as they are merely allowed to be operated in batch mode and complete one water harvest cycle every day. This inevitably makes it rather challenging to deploy MOF-based SAWH for water production at scales. To overcome this challenge, MXene Ti3C2-incorporated UiO-66-NH2 (TUN) cylindrical monoliths (13 mm diameter, 4 mm thickness) with vertically aligned porous networks have been prepared and exhibited greatly enhanced solar heating capacity and atmospheric water adsorption/desorption kinetics. Using TUN monoliths as atmospheric water adsorbents, a novel SAWH device containing a flippable adsorbent stage with dual TUN monolith layers attached on both sides has been fabricated. Such a novel design enables the prototype to produce water in a continuous mode under sunlight irradiation, delivering 57.8 mLH2O kgMOF-1 h-1 of water productivity in a simulated indoor arid environment (20% relative humidity, 298 K). This is the first exploration in continuous water production with MOF-based SAWH, demonstrating a promising way to achieve scalable and low-cost SAWH in arid areas.

Constrained by the unsatisfactory physical adsorption capacity and the low carbon yield from chemical activation, practical utilization of carbon materials for CO2 capture and separation (CCS) remains a huge challenge. Herein, we proposed a novel in-situ activation methodology to prepare a category of porous carbon monoliths in which the potassium ion activation sites are evenly introduced through acid-base reaction, contributing to the high carbon yield, abundant ultramicropores as well as rich nitrogen content. Tested at adsorption temperatures of 0, 25 and 40 °C, the as-prepared carbon monoliths display remarkable static CO2 uptake (7.1, 5.0 and 3.7 mmol/g, respectively) and excellent selective adsorption ability in dynamic breakthrough experiment with a binary mixture of CO2/N2 (68, 63 and 67, respectively). Along with the experiments, the CO2 adsorption mechanism was determined by calculating the adsorption density and adsorption energy on slit pore with various pore sizes and surface functionalities using grand canonical Monte Carlo (GCMC) simulation. The narrow micropores can significantly and effectively increase the CO2adsorption capacity, while the functional groups played the second role.

In this study, NH3 adsorption isotherms for a commercial vanadium-based SCR catalyst coated on a monolith substrate were obtained using a gas flow reactor over a wide range of parameters which have not been performed before in a single study. The isotherms were obtained under different conditions, where adsorption temperature, NH3 concentration, water concentration, washcoat loading, and catalyst oxidation state were varied. For this purpose, a systematic data processing method was developed, which characterizes the dispersion and delay effects in the experimental setup using a residence time distribution model, and artifacts such as NH3 adsorbed in the experimental setup and uncertainties in the washcoat loading were removed. As a result, data from different catalyst samples were integrated, and adsorption isotherms with low data spread and well-defined regions were obtained. This allows the identification of the complex nature of the catalyst and dynamics, where multiple types of adsorption sites are present. For instance, the oxidized catalyst has 50% higher NH3 storage capacity compared to the reduced state of the sample. Moreover, water reduces the NH3 storage capacity at high concentrations (5.0%), whereas at low concentration (0.5%), water increases the NH3 adsorption capacity for an oxidized catalyst. The proposed data processing method can be extended for the analysis of further phenomena in catalysts studied using gas flow reactors, complementing current methods and providing information for models with extended validity and lower parameter correlations.

The advancement of supercapacitors (SCs) is closely bound up with the breakthrough of rational design of energy materials. Freestanding and thick carbon (FTC) materials with well‐organized porous structure is promising SC electrode delivering high areal capacitive performance. However, controllable and sustainable fabrication of such FTC electrode is still of great challenges. Inspired by natural honeycombs with cross‐linked multichannel structure, herein, an innovative molecular‐cooperative‐interaction strategy is elaborately provided to realize honeycomb‐like FTC electrodes. The nitrogen‐doped porous carbon monolith (N‐PCM) is obtained with advantages of interconnect pore structure and abundant nitrogen doping. Such strategy is based on naturally abundant molecular precursors, and free of pore‐templates, expensive polymerization catalyst, and dangerous reaction solvent, rendering it a sustainable and cost‐effective process. Systematic control experiments reveal that strong interactions among molecular precursors promise the structural stability of N‐PCM during carbonization, and rational selection of molecular precursors with chemical blowing features is key step for well‐developed honeycomb‐like pore structure. Interestingly, the optimized sample exhibits hierarchical pore structure with specific surface area of 626.4 m2 g−1 and rational N‐doping of 7.01 wt%. The derived SC electrode with high mass loading of 40.1 mg cm−2 shows an excellent areal capacitance of 3621 mF cm−2 at 1 mA cm−2 and good rate performance with 2920 mF cm−2 at 25 mA cm−2. Moreover, the constructed aqueous symmetric SC and quasi‐solid‐state SC produce high energy densities of 0.32 and 0.27 mWh cm−2, respectively. We believe that such a composition/microstructure controllable method can promote the fabrication and development of other thick electrodes for energy storage devices.

Dry reforming of CH4 /CO2 provides a promising and economically feasible route for the large-scale carbon fixation; however, the coking and sintering of catalysts remain a fundamental challenge. Here we stabilize single-crystalline Ni nanoparticles at the surface of porous single-crystalline MgO monoliths and show the quantitative production of syngas from dry reforming of CH4 /CO2 . We show the complete conversion of CH4 /CO2 even only at 700 °C with excellent performance durability after a continuous operation of 500 hours. The well-defined and catalytically active Ni-MgO interfaces facilitate the reforming reaction and enhance the coking resistance. Our findings would enable an industrially and economically viable path for carbon reclamation, and the "Nanocrystal On Porous Single-crystalline Monoliths" technique could lead to stable catalyst designs for many challenging reactions.

Channeling carbon dioxide The separation of gas molecules with physisorbents can be challenging because there is often a tradeoff between capacity and selectivity. Zhou et al. report a template-free hydrothermal synthesis of the one-dimensional channel zeolite mordenite, in which some silicon was replaced by iron. Rather than forming a powder that requires further shaping, this mechanically stable material self-assembled into monoliths. Iron atoms bound in tetrahedral zeolite sites narrowed the channels and enabled the size-exclusion separation of carbon dioxide (CO 2 ) over nitrogen (N 2 ) and methane. High CO 2 uptake and highly efficient CO 2 –N 2 separation was demonstrated for both dry and humid conditions. Science , aax5776, this issue p. 315

The complete study on the synthesis of biomass waste-based activated carbon monolith from Tectona grandis leaf for supercapacitor electrode materials has been successfully studied. This study was p...

In this study, iron removal was carried out by the adsorption process as a well-known method of removing heavy metal. Natural bentonite with magnetic properties in a monolithic form or Magnetite-Bentonite-based Monolith (MBM) adsorbent was used as an adsorbent to remove Iron (II) ion from the aqueous solution. The magnetic properties of adsorbents are obtained by adding magnetite (Fe3O4), which is synthesized by the coprecipitation process. The characterization of magnetic properties was performed using the Vibrating Sample Magnetometer (VSM). VSM results showed that the magnetic particles were ferromagnetic. Adsorption efficiency, isotherm model, and adsorption kinetics were investigated in a batch system with iron solution concentration varied from 2 to 10 mg/L and magnetite loading at 2% and 5% w/w. The highest removal efficiency obtained reached 89% with a 5% magnetite loading. The best fit to the data was obtained with the Langmuir isotherm (non-linear) with maximum monolayer adsorption capacity (Qo) at 5% magnetic loading MBM adsorbent is 0.203 mg/g with Langmuir constants KL and aL are 2.055 L/g and 10.122 L/mg respectively. The pseudo-first-order (non-linear) kinetic model provides the best correlation of the experimental data with the rate of adsorption (k1) with magnetite loading 2% and 5%, respectively are 0.024 min-1 and 0.022 min-1.

In this work, we prepared a hollow Co3O4 nanoparticles (NPs) immobilized reduced graphene oxide (rGO)/carbon monolith (HCGCM) via a one-step carbonization method. The doping of nanomaterial and transition metal oxide can improve the poor conductivity and low capacitance of pure carbonaceous materials. The optimal addition concentration of polystyrene microspheres as a template provided the HCGCM composite with a hierarchical pore structure and a large specific surface area (1600 cm2/g), which is conducive to generating sufficient electroactive sites. At the same time, three dimensional (3D) interconnected pores shorten ion transport paths and reduced diffusion resistance of ions. Due to the existence of pseudocapacitive behavior, the HCGCM composite, as an electrode material working in a three-electrode system, achieved a high capacitance value of 1106 F/g at a current density of 1 A/g. In two-electrode system, the asymmetric supercapacitor had excellent stability performance and remained about 86.7% capacitance after 5000 cycles test. Moreover, it also exhibited a maximum energy density of 66.7 Wh/kg at power density of 750 W/kg. Thus, the strategy of manufacturing 3D porous electrodes is beneficial to improve the overall electrochemical performance of supercapacitors.

Recently, metal organic frameworks (MOFs) derived porous carbon (PC) was integrated with phase change materials (PCMs) to form composite with enhanced thermal conductivity and stability. However, the aggregation of PC particles during carbonization results in low utilization of supporting material and decrease of loading capacity. In this research, Cu foam monolith was decorated with highly dense nanorods (NRs) to provide numerous attached sites for PC particles. Stearic acid (SA) was then filled into the PC/NRs support to prepare a SA-based hierarchical composite (SA@PC/NRs). The hierarchical composite exhibits enhanced loading capacity (42%) and thermal conductivity (0.81W/mK) than that of referent SA@PC/CF and SA@PC, as well as improved energy storage efficiency, durability and shape-stability. The hierarchical composite PCM allows light-driven thermal energy storage with high conversion and storage efficiency, indicating its potential applications in solar-energy utilization and storage.

Noble metal-based electrocatalysts present high activities for methanol oxidation reaction (MOR), but are limited by their high cost, low stability and poor resistance to carbon monoxide (CO) poisoning. The development of active and stable non-noble metal electrocatalysts for MOR is desired, but remains a challenge. Herein, we report a simple strategy to make copper nanocrystal/nitrogen-doped carbon (Cu/N-C) monoliths, which can serve as active and robust electrodes for MOR. Copper nanocrystals were electrochemically deposited onto a conductive polyaniline hydrogel and calcined to form Cu/N-C monolith, where the active copper nanocrystals are protected by nitrogen-doped carbon. Owing to their extremely high electrical conductivity (1.25 × 105 S cm−1) and mechanical robustness, these Cu/N-C monoliths can be directly used as electrodes for MOR, without using substrates or additives. The optimal Cu/N-C (FT) @500 monolith shows a high MOR activity of 189 mA cm−2 at 0.6 V vs. SCE in alkaline methanol solution, superior to most of reported Cu-based MOR catalysts. Cu/N-C (FT)@500 also presents a better stability than Pt/C catalyst in the long-term MOR test at high current densities. Upon carbon monoxide (CO) poisoning, Cu/N-C (FT)@500 retains 96% of its MOR activity, far exceeding the performance of Pt/C catalyst (61% retention). Owing to its facile synthesis, outstanding activity, high stability and mechanical robustness, Cu/N-C (FT)@500 monolith is promising as a low-cost, efficient and CO-resistant electrocatalyst for MOR.

Deactivation of honeycomb V2O5-WO3/TiO2 catalysts by arsenic has been studied widely in coal-fired power plants but rarely in glass furnaces. In this paper, deactivated catalysts that had been used for more than 4000 h were analyzed. We maintained the catalysts in their original monolith shape to retain their adhered substance and used appropriate methods to strip the substance layer by layer. With various characterization techniques, it was determined that the adhered substance was composed almost entirely of Na2SO4 and CaSO4. We also quantified the penetration depth of arsenic visually, which was more than 370 μm. A three-stage penetration and deactivation process induced by arsenic was proposed. It was pointed out that molten and volatile As2O3 played a key role in the deactivation process, while substances in the solid state had little impact on the deep bulk of the catalyst. In this study, we proposed an integrated deactivation process consisting of adhesion, penetration, and deactivation in a honeycomb V2O5-WO3/TiO2 catalyst by arsenic in a glass furnace. Finally, we also provided guidance on alleviating the deactivation caused by arsenic. The key is to convert molten and volatile As2O3 to solid-state substances before it contacts the catalyst.

Розглянуто актуальність питання щодо вдосконалення методологічних основ проєктування технологій охорони підготовчих виробок, особливо в умовах відпрацювання вугільних пластів на великих глибинах та у слабких бічних породах. Здійснено аналіз існуючих методик вибору технологій охорони підготовчих виробок. Встановлено, що цими методиками регламентуються конкретні технології та обмежується можливість розгляду інноваційних рішень. Виключенням є методика, що запропонована у ДВНЗ ДонНТУ. Але вона потребує удосконалення з метою усунення на початковому етапі недоцільних технологій охорони виробок без проведення громіздких розрахунків за економічними критеріями. Тому метою дослідження стало вдосконалення методики вибору технологій охорони підготовчих виробок, яка б передбачала поетапний розгляд заходів щодо забезпечення експлуатаційного стану виробки та їх економічне порівняння. Запропоновано графічну інтерпретацію методики та її опис. Під час виконання окремих етапів методики аналізуються способи та засоби охорони виробок. Для цього може бути використано запропоновану класифікацію способів охорони підготовчих виробок, що передбачають вплив на навколишній масив, та рекомендації щодо визначення конструктивних особливостей засобів охорони. Висунуто припущення, що отримані результати можуть бути підґрунтям для перевірки відповідності області використання та уточнення параметрів існуючих або розробки нових технологій охорони підготовчих виробок у складних гірничо-геологічних умовах.

The wholeness of the stone monolith is saved when separating of it occur with the diamond wire machines. However, there are some problems and questions – what are the optimal dimensions of the monolith and the angles of drilling for contouring with diamond wire or what kind of the machines and tools are better for separating the natural stone monolith. The process of the natural stone monolith separating with diamond wire saw leads to quantitative losses of stone. The number of the exposure planes, the monolith dimensions, the diameter of drillholes and the diameter of the diamond wire. All these parameters affect the amount of the quantitative losses. Qualitative losses of the stone are lacking with using the diamond wire. Nevertheless, these losses appear because of the diamond wire deviation from the designed cutting plane, uneven frazzle of the diamond beads, increasing of the diamond wire diameter until cutting.

In this work, the optimization of a monolith reactor 3-dimensional model is carried out, for a first order reaction, isothermal conditions and fully developed laminar flow. The obtained results are consistent with the optimal reactor design obtained under plug flow conditions, namely a maximum conversion reactor features maximum channel width, minimum hydraulic diameter, and maximum fluid velocity determined by an upper bound that is a function of the channel’s width, height, and the capital cost to compression cost ratio.

A polyethylenimine-grafted cellulose monolith was developed for efficient bacterial capture in a continuous flow system. The amino-functionalized monolith showed superior capture capacity for high concentration of both gram-negative (Escherichia coli) and gram-positive (Bacillus subtilis) bacteria compared with the unmodified one. The efficiency and structural stability of the monolith were consistent during bacterial filtering at a high flow velocity. Bacteria were observed to be anchored to the skeleton surface of the monolith. The performance was attributed to the well-interconnected porous structure and strong electrostatic interaction with cells, which endowed the large surface area with retention force allowing for the local adhesion of bacteria in a flow process.

BACKGROUND Inadequate marginal fit of fixed restorations leads to plaque accumulation, recurrent caries and periodontal problems. The purpose of this experimental study is to evaluate and compare the marginal fit/gap of computer-aided design and computeraided manufacturing (CAD/CAM) fabricated zirconia copings and zirconia full contoured monolith crowns fabricated on type IV gypsum die having a definite cement spacer thickness of 0.05mm. METHODS This is an in-vitro experimental study carried out from November 2018 to November 2019. A master stainless steel die was used to make 52 type IV die stone models which were randomly divided into 2 groups of 26 samples each. Group 1: zirconia copings and group 2: zirconia monolith full contoured crowns. These restotations were fabricated using CAD/CAM. The marginal gap of each zirconia copings and zirconia full contoured crowns was assessed using scanning electron microscopic analysis on four different pre-marked points (GEMINI SEM 500; ZEISS). Observations were tabulated and analyzed statistically. Independent t-test was used to compare the measurements between zirconia copings & zirconia monolith crowns. RESULTS The least marginal gap observed was for group 2 (zirconia full contoured crown) with a mean value of 29.88 ± 9.16 μm while that of group1 (zirconia coping) was 73.64 ± 28.13 μm. There was a statistically significant difference in the measurements between zirconia copings and zirconia full contoured monolith crowns (P - value < 0.001). There was statistically significant difference in each side of zirconia monolith crowns when compared to the corresponding side of zirconia copings (P - Value < 0.001). CONCLUSIONS CAD/CAM milled full contoured zirconia crowns showed least marginal discrepancy when compared to zirconia copings. All samples had marginal gap within the clinically acceptable range of 120 μm. KEY WORDS Monolith, Zirconia Crowns, Zirconia Copings, Full Contoured Crowns, CAD-CAM

The adopted ligand type of a palladium precursor has a great influence on the microstructure, morphology and catalytic performance of obtained Pd-based monolith catalysts by a one-step method with ...

This work developed a fast and simple method for the quantification of two important β-agonists, ractopamine (RAC) and clenbuterol (CLEN) in animal urines. The method was based on micro-extraction by a mixed mode monolithic material and analysis by HPLC-UV and UHPLC-Q ExactiveTM Plus Orbitrap mass spectrometer. A mixed functional monolith with nonpolar ester-based structure containing polar carboxylic groups was thermally synthesized in situ in the pipette tips. The material combines both hydrophobic and ionic interactions. Parameters including conditions and composition of reagents for the in-pipette tip monolith synthesis, as well as the extraction process, were investigated and optimized. The procedure for extraction is 800 μL washing solvent of 10:90 (v/v) ACN:water and 150 μL eluting solvent of 30:70 (v/v) ACN:200 mM acetate buffer pH 4.0. Extraction efficiencies of 92% and 100% for RAC and CLEN, respectively, were achieved within 5 min with total organic solvent consumption of 395 μL. The extracts of spiked cattle and swine urines were analyzed by HPLC-UV and UHPLC-Q ExactiveTM Plus Orbitrap mass spectrometer. Good recovery with acceptable precision was observed. The mass spectrometry data confirmed efficient matrix removal by the synthesized extraction sorbent allowing routine analysis by the HPLC-UV method.

Experiments were conducted for developing an on board MOFs hydrogen storage system by cryo-adsorption in terms of adsorption equilibrium and charge/discharge characteristic of the adsorbent bed. MIL-101 was synthesized by hydrothermal method, the expanded natural graphite (ENG) and a honeycomb heat exchanging device were then introduced for monolith and heat conducting enhancement. Structural characterization and measurement of thermal conductivity were performed on the MIL-101 and its composites synthesized by mixing ENG with different mass ratios. Adsorption equilibrium data of hydrogen on the MIL-101 and MEI-01 (composite formed by adding ENG with a mass ratio 0.1) were measured at a temperature-pressure range from 77.15K to 87.15 K and 0–6 MPa. Accuracies of results predicted by Langmuirian equations were compared, Toth equation and Henry law were then employed to calculate the isosteric heat of hydrogen adsorption. Charge and discharge tests were conducted under the flow rate 20 L · m i n − 1 on a 3.2 L conformable vessel respectively filled MIL-101, MIL-101+honeycomb heat exchanging device and MEI-01. It shows that the isosteric heats on two samples are similar and are about 3.1 kJ · m o l − 1 − 7.4 kJ · m o l − 1 ; the honeycomb heat exchanging device is better on weakening the thermal effect of the adsorbent bed than adding the ENG. It suggests that employing a conformable shape vessel equipped with a honeycomb heat exchanging device is a feasible solution to an on board MOFs hydrogen storage system.

The removal of mercury from the waterbody remains a severe challenge in ensuring environmental safety due to its highly toxic and non-biodegradable properties. Adsorption is an evidently effective method for heavy metal removal in water. This research aims to study the mercury (II) ion adsorption behavior in aqueous solution onto extruded natural bentonite in monolithic structure, bentonite-based monolith (BBM) adsorbent. BBM was characterized by XRD, BET, and SEM, the results verify BBM could improve adsorption performance assumed on its structure. Adsorption efficiency, isotherm model, and adsorption kinetic were investigated. Experiments were performed in a lab-scale batch reactor with mercury solution concentration varied from 1 to 5 mg/L. The maximum adsorption efficiency discovered to be 63,9%. The experimental data fitted well to Langmuir isotherm (non-linear) and kinetic model pseudo first order (non-linear), revealing the maximum monolayer capacity (Qo) of BBM to be 0,187 mg/g with Langmuir constants KL and aL are 0,215 L/g dan 1,151 L/mg respectively. These value confirms that BBM adsorbent encompasses tremendous potential for mercury (II) ion removal in a solution.

There are various methodologies to account for mass transfer within non-uniformly distributed washcoats in monolith reactors in 1D models (axially). However, 1+1D models (axially/radially) fail to capture local variations in mass transfer from different coating thicknesses or cracks. In this paper, we present a novel way to account for local material properties in a washcoated monolith reactor. The suggested method uses an existing 1+1D modelling framework and sectionalizes the washcoat into multiple tangential segments which are solved independently. Intelligent gravimetric analysis and scanning electron microscopy are used in combination to calculate local effective diffusivity as an input for each simulation. The new model is compared to the original 1+1D model using NO light-off simulations. The new model predicted increased conversion at elevated temperatures, where mass transfer limitations are present, due to the higher porosity in the corners. The simulation time for each model was similar due to the parallelizable nature of the new model.

Lead halide perovskite quantum dots (PQDs) are reported as a promising branch of perovskites, which have recently emerged as a field in luminescent materials research. However, before the practical applications of PQDs can be realized, the problem of poor stability has not yet been solved. Herein, we propose a trioctylphosphine (TOP)-assisted pre-protection low-temperature solvothermal synthesis of highly stable CsPbBr3/TiO2 nanocomposites. Due to the protection of branched ligands and the lower temperature of shell formation, these TOP-modified CsPbBr3 PQDs are successfully incorporated into a TiO2 monolith without a loss of fluorescence intensity. Because the excellent nature of both parent materials is preserved in CsPbBr3/TiO2 nanocomposites, it is found that the as-prepared CsPbBr3/TiO2 nanocomposites not only display excellent photocatalytic activity but also yield improved PL stability, enabling us to build highly stable white light-emitting diodes and to photodegrade rhodamine B.