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Although CO2 contributes significantly to global warming, it also offers potential as a raw material for the production of hydrocarbons such as CH4, C2H4 and CH3OH. Electrochemical CO2 reduction reaction (eCO2RR) is an emerging technology that utilizes renewable energy to convert CO2 into valuable fuels, solving environmental and energy problems simultaneously. Insights gained at any individual scale can only provide a limited view of that specific scale. Multiscale modeling, which involves coupling atomistic‐level insights (density functional theory, DFT) and (Molecular Dynamics, MD), with mesoscale (kinetic Monte Carlo, KMC, and microkinetics, MK) and macroscale (computational fluid dynamics, CFD) simulations, has received significant attention recently. While multiscale modeling of eCO2RR on electrocatalysts across all scales is limited due to its complexity, this review offers an overview of recent works on single scales and the coupling of two and three scales, such as "DFT+MD", "DFT+KMC", "DFT+MK", "KMC/MK+CFD" and "DFT+MK/KMC+CFD", focusing particularly on Cu‐based electrocatalysts as copper is known to be an excellent electrocatalyst for eCO2RR. This sets it apart from other reviews that solely focus exclusively on a single scale or only on a combination of DFT and MK/KMC scales. Furthermore, this review offers a concise overview of machine learning (ML) applications for eCO2RR, an emerging approach that has not yet been reviewed. Finally, this review highlights the key challenges, research gaps and perspectives of multiscale modeling for eCO2RR. [ABSTRACT FROM AUTHOR]

Conversion of hemicellulose streams and the constituent monosaccharides, xylose, arabinose, glucose, mannose, and galactose, was conducted to produce value‐added chemicals, including furfural, hydroxymethylfurfural (HMF), levulinic acid and anhydrosugars. The study aimed at developing a kinetic model relevant for direct post‐Organosolv hemicellulose conversion. Monosaccharides served as a tool to in detail describe the kinetic behavior and segregate contribution of hydrothermal decomposition and acid catalyzed dehydration at the temperature range of 120–190 °C. Catalyst free aqueous media demonstrated enhanced formation of furanics, while elevated temperatures led to significant saccharide isomerization. The introduction of sulfuric and formic acids maximized furfural yield and significantly reduced HMF concentration by facilitating its rehydration into levulinic acid (46 mol%). Formic acid additionally substantially enhanced formation of anhydrosaccharides. An excellent correlation between modeled and experimental data enabled process optimization to maximize furanic yield in two distinct hemicellulose streams. Sulfuric acid‐containing hemicellulose stream achieved the highest furfural yield after 30 minutes at 238 °C, primarily due to the high Ea for pentose dehydration (150–160 kJ mol−1). Contrarily, formic acid‐containing hemicellulose stream enabled maximal furfural yield at more moderate temperature and extended reaction time due to its lower Ea for the same reaction step (115–125 kJ mol−1). [ABSTRACT FROM AUTHOR]

The Haber–Bosch process is a cornerstone in the field of ammonia production and represents a decisive advance in industrial chemistry. This method, developed in the early 20th century, revolutionizes agriculture and enables the mass production of fertilizers. As the world strives for sustainable energy and environmental protection, alternative methods such as the photo/photoelectrocatalytic nitrogen reduction reaction (NRR) are gaining momentum. By using sunlight, electricity, or a combination of both, these approaches promise sustainable ammonia production with renewable energy sources and innovative materials. Researchers are trying to understand the underlying principles, mechanisms, and advances of these methods to overcome the challenges and optimize their effectiveness. This research is a step toward sustainable energy and agriculture, and offers a greener and more efficient way forward. This review looks at advances in sustainable ammonia production, particularly through photo‐ and photoelectrocatalytic NRRs. It examines the hurdles in implementing these methods and provides an overview of the fundamentals of nitrogen fixation and a comparison of current mechanisms. In addition, thermodynamic, theoretical, and computational studies of these processes are summarized. Various photocatalysts and photoelectrocatalysts used for ammonia production are also presented. [ABSTRACT FROM AUTHOR]

Carbon nitrides, metal‐free semiconducting materials, have unique molecular structure and semiconducting properties which have inspired researchers to utilize them as photocatalysts for the sustainable production of hydrogen. However, they suffer from a few drawbacks including fast charge‐carrier recombination rate and low charge transfer efficiency owing to their amorphous and less conducting wall structure which remain as significant challenge for achieving breakthrough in photocatalytic water splitting. Herein, the study reports a supramolecular approach of coupling thiourea and trimesic acid for designing highly efficient C‐doped carbon nitride photocatalysts in which the π‐electron density is precisely manipulated. The developed C‐doped carbon nitride demonstrates the fine‐tuned band positions, the mitigated electron–hole recombination, and enhanced conductivity, resulting in the facilitation of significantly enhanced hydrogen generation through the photocatalytic water splitting under the solar‐simulated light. The position and distribution of C‐doping in the carbon nitride framework are characterized by using advanced analytical techniques such as X‐ray photoelectron spectroscopy, near‐edge X‐ray absorption fine structure spectroscopy, and electron paramagnetic resonance spectroscopy together with the first‐principles studies of the electronic structure and energetics of doping. The remarkable increase in photocatalytic hydrogen generation by using developed C‐doped carbon nitride brings one step closer to achieving a green hydrogen economy. [ABSTRACT FROM AUTHOR]

Artificial ammonia synthesis via the Haber‐Bosch process is environmentally problematic due to the high energy consumption and corresponding CO2 ${_2 }$ emissions, produced during the reaction and before hand in hydrogen production upon methane steam reforming. Photocatalytic nitrogen fixation as a greener alternative to the conventional Haber‐Bosch process enables us to perform nitrogen reduction reaction (NRR) under mild conditions, harnessing light as the energy source. Herein, we systematically review first‐principles calculations used to determine the electronic/optical properties of photocatalysts, N2 adsorption and to expound possible NRR mechanisms. The most commonly studied photocatalysts for nitrogen fixation are usually modified with dopants, defects, co‐catalysts and Z‐scheme heterojunctions to prevent charge carrier recombination, improve charge separation efficiency and adjust a band gap to for utilizing a broader light spectrum. Most studies at the atomistic level of modeling are grounded upon density functional theory (DFT) calculations, wholly foregoing excitation effects paramount in photocatalysis. Hence, there is a dire need to consider methods beyond DFT to study the excited state properties more accurately. Furthermore, a few studies have been examined, which include higher level kinetics and macroscale simulations. Ultimately, we show there is still ample room for improvement with regard to first principles calculations and their integration in multiscale models. [ABSTRACT FROM AUTHOR]

The improvement of high‐Z‐based metallic nanostructures as radiosensitizers with high monolithicity and versatility by superadditive therapeutic track and the good protective effect is considerable, but they are limited by some problems such as nonideal selectivity for the target tissue. In this study, nanosystems were developed to enhance the efficacy of radiotherapy and reduce cancer cell survival based on innovative gold (Au) functionalized oxygen‐single‐walled carbon nanotubes (O‐SWCNTs). We illustrate the use of folic acid (FA) as a targeting agent and bovine serum albumin (BSA) to stabilize the physiological environment and increase durability. The physical and chemical properties of the nanosystems were evaluated using transmission electron microscopy (TEM), selected area electron diffraction (SAED), dynamic light scattering (DLS), zeta potential, X‐ray diffraction (XRD), ultraviolet–visible (UV–Visible), and Fourier transform infrared (FTIR) techniques. Finally, the MTT assay was used to investigate the therapeutic effects of nanoparticles in the 4 T1 mouse breast cancer model in the presence and absence of X‐rays. So, the cancer cells experienced a more effective reduction in survival after receiving O‐SWCNTs‐Au‐BSA‐FA + 8 Gy than O‐SWCNTs‐BSA, Au‐BSA‐FA, and O‐SWCNTs‐Au‐BSA + 8 Gy groups. [ABSTRACT FROM AUTHOR]

Ethylene epoxidation is industrially and commercially one of the most important selective oxidations. Silver catalysts have been state‐of‐the‐art for decades, their efficiency steadily improving with empirical discoveries of dopants and co‐catalysts. Herein, we perform a computational screening of the metals in the periodic table, identify prospective superior catalysts and experimentally demonstrate that Ag/CuPb, Ag/CuCd and Ag/CuTl outperform the pure‐Ag catalysts, while they still confer an easily scalable synthesis protocol. Furthermore, we show that to harness the potential of computationally‐led discovery of catalysts fully, it is essential to include the relevant in situ conditions e.g., surface oxidation, parasitic side reactions and ethylene epoxide decomposition, as neglecting such effects leads to erroneous predictions. We combine ab initio calculations, scaling relations, and rigorous reactor microkinetic modelling, which goes beyond conventional simplified steady‐state or rate‐determining modelling on immutable catalyst surfaces. The modelling insights have enabled us to both synthesise novel catalysts and theoretically understand experimental findings, thus, bridging the gap between first‐principles simulations and industrial applications. We show that the computational catalyst design can be easily extended to include larger reaction networks and other effects, such as surface oxidations. The feasibility was confirmed by experimental agreement. [ABSTRACT FROM AUTHOR]

Polyethylene terephthalate (PET) is a non‐degradable single‐use plastic and a major component of plastic waste in landfills. Chemical recycling is one of the most widely adopted methods to transform post‐consumer PET into PET's building block chemicals. Non‐catalytic depolymerization of PET is very slow and requires high temperatures and/or pressures. Recent advancements in the field of material science and catalysis have delivered several innovative strategies to promote PET depolymerization under mild reaction conditions. Particularly, heterogeneous catalysts assisted depolymerization of post‐consumer PET to monomers and other value‐added chemicals is the most industrially compatible method. This review includes current progresses on the heterogeneously catalyzed chemical recycling of PET. It describes four key pathways for PET depolymerization including, glycolysis, pyrolysis, alcoholysis, and reductive depolymerization. The catalyst function, active sites and structure‐activity correlations are briefly outlined in each section. An outlook for future development is also presented. [ABSTRACT FROM AUTHOR]

Summary: Hydrogen for the use in electrochemical fuel cells (FCs) can be obtained from diesel's sourced energy. A small scale process of the catalytic auto‐thermal reforming (ATR) with the operational water‐gas shift (WGS) for the production of hydrogen with suitable purity grade as a resource in the high temperature polymer membrane redox FCs (HT‐PEMFCs) for auxiliary power systems was proposed. The reactors for hydrocarbon ATR dehydrogenation reactions, WGS processor serial treatment and downstream were designed. Technology was simulated using Aspen Plus software. Gibbs minimization was applied to validate the product compound composition for both units' yields, modelling was analysed, and the heat at the ATR device fluid inlet, the potential of pressure, feed, the influence of the oxygen to carbon (C) amount ratio, and the steam to total indicated C equivalent were investigated. one dimensional models were used for ATR/WGS. The first was considered as a plug flow, while the latter as packed‐bed vessel. Particular kinetic parameters were estimated from literature; other functional conditions were specified. Combined sequential results, assessed from calculations, allow for a successful engineered construction, operation and intensification of ATR, which requires a good physical understanding, but also control of thermodynamic equilibria, transport phenomena and mechanistic chemical rates. [ABSTRACT FROM AUTHOR]

The heterogeneously catalyzed hydrogenation of biomass‐ or CO2‐derived glycolic acid (GA) is a renewable pathway for obtaining the bulk chemical ethylene glycol (EG). In this study, the reaction network of the aqueous‐phase hydrogenation of GA is investigated over a Ru/C catalyst. Beside this target reaction, both undesired parallel reactions (such as the hydrogenation of GA to acetic acid (AcA)) and unwanted consecutive reactions (such as over‐hydrogenation) can occur. These reactions are experimentally assessed by employing different (possible) reaction intermediates and products (EG, AcA, glycolaldehyde, acetaldehyde, and ethanol) as reactants. The data for all individual reactions as well as the overall GA hydrogenation at different reaction temperatures (120–180 °C) is combined to propose a catalytic reaction pathway network and to develop a corresponding microkinetic model. The kinetic model describes the catalytic data in the range up to 150 °C, where EG is the main reaction product, with high accuracy. It is shown that selectivity for EG is highest at 120 °C (up to ca. 70%) and decreases strongly with increasing temperatures both due to the parallel reaction of GA into acetic acid (AcA), which has a significantly higher activation energy than the overall hydrogenation of GA into EG, and due to degradation of EG into ethanol and other volatile products. Temperatures exceeding 150 °C predominantly yield volatile products, suggesting low yields of EG or AcA at higher temperatures despite enhanced GA conversion. [ABSTRACT FROM AUTHOR]

Electrochemical reduction reaction of CO2 (eCO2RR) to produce valuable chemicals offers an attractive strategy to solve energy and environmental problems simultaneously. We have mapped out entire reaction pathways of eCO2RR to CO on Cu(100), including all intermediates and transition states using first‐principles simulations. To accurately account for the solvent effect, the reaction was investigated with and without explicit water molecules, highlighting the limitations of the often (mis)used vacuum reaction pathway simplification. The results show that the reduction reaction was initiated under neutral pH conditions at an applied potential of −0.11 V (RHE, reversible hydrogen electrode) and all elementary reactions were thermodynamically favorable, while an applied potential of −1.24 V is required to ensure that all reactions exhibit spontaneous behavior. Detailed analysis revealed that solvation significantly influences the stability of the adsorbates and intermediates. Its inclusion notably alters the calculated reaction kinetics and energetic parameters by lowering the barrier energies and Gibbs free energies of all reactions. CO production proceeded mainly via the COOH* pathway (CO2 →trans‐COOH*→cis‐COOH*→CO*+OH*→CO*→CO). The use of water as a more sustainable and cost‐effective solvent is compared to other options such as organic solvents, ionic liquids and mixed solvent systems, which are less sustainable and more expensive. [ABSTRACT FROM AUTHOR]

In this work, the kinetic model based on the previously developed metabolic and glycan reaction networks of the ovarian cells of the Chinese hamster ovary (CHO) cell line was improved by the inclusion of transcriptomic data that took into account the values of the RPKM gene (Reads per Kilobase of Exon per Million Reads Mapped). The transcriptomic (RNASeq) data were obtained together with metabolic and glycan data from the literature, and the concentrations with RPKM values were collected at several points in time from two fed‐batch processes. First, the fluxes were determined by regression analysis of the metabolic data, then these fluxes were corrected by using the fold change in gene expression as a measure of enzyme concentrations. Next, the corrected fluxes in the kinetic model were used to calculate the concentration profiles of the metabolites, and literature data were used to evaluate the predicted results of the model. Compared to other studies where the concentration profiles of CHO cell metabolites were described using a kinetic model without consideration of RNA‐Seq data to correct the fluxes, this model is unique. The additional integration of transcriptomic data led to better predictions of metabolic concentrations in the fed‐batch process, which is a significant improvement of the modelling technique used. [ABSTRACT FROM AUTHOR]

As one of the most demanded dicarboxylic acids, adipic acid can be directly produced from renewable sources. Hexoses from (hemi)cellulose are oxidized to aldaric acids and subsequently catalytically dehydroxylated. Hitherto performed homogeneously, we present the first heterogeneous catalytic process for converting an aldaric acid into muconic and adipic acid. The contribution of leached Re from the solid pre‐reduced catalyst was also investigated with hot‐filtration test and found to be inactive for dehydroxylation. Corrosive or hazardous (HBr/H2) reagents are avoided and simple alcohols and solid Re/C catalysts in an inert atmosphere are used. At 120 °C, the carboxylic groups are protected by esterification, which prevents lactonization in the absence of water or acidic sites. Dehydroxylation and partial hydrogenation yield monohexenoates (93 %). For complete hydrogenation to adipate, a 16 % higher activation barrier necessitates higher temperatures. [ABSTRACT FROM AUTHOR]

Experimental and modeling work, described in this article, is focused on the metabolic pathway of Chinese hamster ovary (CHO) cells, which are the preferred expression system for monoclonal antibody protein production. CHO cells are one of the primary hosts for monoclonal antibodies production, which have extensive applications in multiple fields like biochemistry, biology and medicine. Here, an approach to explain cellular metabolism with in silico modeling of a microkinetic reaction network is presented and validated with unique experimental results. Experimental data of 25 different fed‐batch bioprocesses included the variation of multiple process parameters, such as pH, agitation speed, oxygen and CO2 content, and dissolved oxygen. A total of 151 metabolites were involved in our proposed metabolic network, which consisted of 132 chemical reactions that describe the reaction pathways, and include 25 reactions describing N‐glycosylation and additional reactions for the accumulation of the produced glycoforms. Additional eight reactions are considered for accumulation of the N‐glycosylation products in the extracellular environment and one reaction to correlate cell degradation. The following pathways were considered: glycolysis, pentose phosphate pathway, nucleotide synthesis, tricarboxylic acid cycle, lipid synthesis, protein synthesis, biomass production, anaplerotic reactions, and membrane transport. With the applied modeling procedure, different operational scenarios and fed‐batch techniques can be tested. [ABSTRACT FROM AUTHOR]

Summary: A tannins‐rich chestnut extract was used to enhance the antioxidant and antibacterial properties of chitosan‐based film materials. The favourable mechanical properties of the novel material enabled its application in the preparation of the sachets that were used for packing and storage of filled fresh pasta. The fresh pasta ageing progressed in conventional refrigerated storage conditions of 8 °C with 60 ± 2% relative humidity in the absence of light for 60 days. The rapid moisture mobility between a starchy food and sachets during the first 9 days of storage induced retrogradation of the fresh pasta, whereby total phenolic content show dependency on moisture throughout the shelf life. Active components within the sachet prevented microbial growth on the food surface during the entire 60 days. [ABSTRACT FROM AUTHOR]

Chitin displays a highly rigid structure due to the vast intra‐ and intermolecular hydrogen bonding, thus hindering its dissolution and deacetylation using most solvents. Deep eutectic solvents (DESs) are special and environmentally friendly solvents composed of a hydrogen bond acceptor and a hydrogen bond donor. This allows them to dissolve chitin by disturbing its natural hydrogen bonding while establishing new bonds, hence turning the polymer more susceptible to solvents. Therefore, four distinct DESs (choline chloride‐lactic acid ([Ch]Cl:LA), choline chloride:oxalic acid ([Ch]Cl:OA), choline chloride:urea ([Ch]Cl:U) and betaine‐glycerol (Bet:G)) were applied in chitin dissolution, being the most performant ones further applied in its homogenous N‐deacetylation with NaOH. In this work, a milder and more biocompatible approach was carried out by using 30 wt% NaOH at 80°C, instead of the typical ≥40 wt% NaOH at temperatures ≥100°C. Herein, the reaction process took up to 18 hours, being the results analyzed through ATR‐FTIR. Chitin was converted into chitosan with a 70‐80% degree of deacetylation (DDA) in a short period while using homogenous conditions. These promising results provide the first proof of concept of the ability of Bet:G and [Ch]Cl:LA‐based DESs to be used as a greener approach for the chitin homogeneous N‐deacetylation. [ABSTRACT FROM AUTHOR]

Photo‐electro‐catalytic oxidation reactions of 1,6‐hexanediol were carried out in a coil‐type continuous‐flow microreactor with an immobilized TiO2 catalyst material. Bio‐based adipic acid was formed as the only intermediate product before the total mineralization process. The production was stable, enabling green, selective and continuous resource conversion, but with low, non‐optimized yields. In addition, the catalyzed chemical kinetics was modeled, based on mechanisms as well as approximated rate‐determining steps. The Butler‐Volmer relation was used for activation. The electro‐catalytic oxidative pathway was demonstrated to dominate over photo‐catalysis, also on account of the band gap characteristics of the titania nanotube electrode. [ABSTRACT FROM AUTHOR]

Summary: Natural gas from stranded sources is being predominantly flared, and there is a growing demand for new technologies for its utilisation, where electrification, flexibility, and modularity play an important role. Plasma‐activated methane partial oxidation reaction was studied in a designed dielectric barrier discharge ionisation reactor unit, producing value‐added platform chemicals, namely, methanol, formaldehyde, intermediate formic acid, acetic acid, and paraformaldehyde at ambient temperature and atmospheric pressure. The effects of various process parameters, such as voltage, total convertible gas flow rate, and reagent ratio relationship, were considered. In addition, coupling of the following catalytic materials with plasma was examined: alumina (Al2O3), chabazite, ferrierite, microporous beta zeolite, silica (SiO2) glass beads, ZSM‐5 (MFI), Fe on H‐ZSM‐5 and Al2O3, Mo on H‐ZSM‐5, TiO2 and SiO2, and Pd on Al2O3. In the liquid product, 21.5% CH3OH, 20.4% CH2O, 0.3% HCOOH, and 2.4% CH3COOH were measured when using pure plasma, and a maximum aggregate yield of the organic oxygenate compounds of 5.21 mol.% was achieved. The usage of shaped silicate surface increased the selectivity towards synthesised oxygen‐containing structures, while the application of alumino‐silicate mixture constituents reduced it. It was determined that elementary covalently bonded carbon was formed inside pores when pure zeolites were used. Fe‐ and Pd‐based heterogeneous catalysts favoured the complete exothermic combustion of CH4 feedstock reactant species, and the liquid product consisted only of water in the Pd‐ case. The utilisation of Mo/H‐ZSM‐5 resulted in a 46% increased yield of formalin. A mechanism for the role of Mo was proposed, where Mo oxidises methanol to formaldehyde and the metal is reoxidised in plasma. [ABSTRACT FROM AUTHOR]

Summary: A high abundance of methane and its relatively low price make it an attractive raw feedstock for the production of ethylene, which is in the consumer demand in recent years. Direct catalytic nonoxidative conversion is interesting, because it could be utilized on natural gas well sites. Monometallic and bimetallic Fe and Mo catalysts were prepared for the purpose of the coupling to ethane and ethene. Three supported materials were synthesized with the following loading of metal: 2.5‐wt% Fe, 5.0‐wt% Fe, and 2.5‐wt% Mo on HZSM‐5. Process' chemical reactions were also catalyzed with a constant 2.5‐wt% Mo/HZSM‐5, which had different amounts of Fe, namely, 0.5, 1.0, and 2.5 wt%. Fourier transform infrared (FTIR), N2 adsorption/desorption, NH3 temperature‐programmed desorption (TPD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and X‐ray diffraction (XRD) were applied for characterization. Coke, accumulated on spent solids, was determined by thermogravimetric analysis (TGA). Activity was evaluated in quartz‐packed bed reactor. All surfaces suffered from deactivation due to carbon formation. The addition of Fe to Mo increased CH4 reacted. The highest selectivity for alkenes was achieved over 1.0‐wt% Fe to 2.5‐wt% Mo/HZSM‐5. At the peak of performance, the C‐based reactivity was 52% for olefins and 2% for alkanes. Stability was accomplished over 2.5‐wt% Fe/HZSM‐5, where the rate of C2 synthesis was comparatively stable for 20 hours of the time on stream. The selective C‐basis yield for C2H4 and C2H6 was 36% and 23%, respectively. The lowest measured quantity of (carbonaceous) by‐products was deposited on 2.5‐wt% Fe/HZSM‐5 after 26 hours. Propylene was detected very limitedly. [ABSTRACT FROM AUTHOR]

Monometallic 50 wt % Cu/Al2O3 catalyst and bimetallic catalysts containing 25 wt % Co/25 wt % Cu, 25 wt % Co/25 wt % Fe, and 25 wt % Cu/25 wt % Fe, supported on Al2O3, were prepared by impregnation and coimpregnation methods. For bimetallic catalysts, metal oxides were in the form of spinel oxides, which exhibited a strong metal-support interaction. The decomposition of methane over these catalysts led to the formation of pure hydrogen and carbon nanotubes on their surfaces. The activation energy, total carbon yield, and amount of hydrogen formed, by using the prepared catalysts, were in agreement with the metal dispersion and acid-base site ratio on the surface of the catalysts. Cu−Fe/Al2O3 catalyst exhibited a stable hydrogen formation rate of 58 mmol min−1 g−1 at a temperature of 650 °C. All catalysts exhibited deactivation after 500 min, which occurred due to the formation of carbon on the surface of the catalysts. The carbon material deposited predominantly assumed the form of multiwalled carbon nanotubes, as evidenced by high-resolution TEM and Raman spectroscopy. Thermogravimetric analysis finally confirmed that Cu−Fe/Al2O3 exhibited a higher yield of multiwalled carbon nanotubes. [ABSTRACT FROM AUTHOR]

Cu-based bifunctional materials were examined for carbon dioxide conversion, thus producing the syngas from hydrogen, which can be attained using surplus electrical energy. Catalysts were synthesized by deposition-precipitation fabrication method, i.e., copper on Al2O3, CeO2, SiO2, TiO2, and ZrO2. To investigate chemical reaction kinetics, the turnover was screened in a parallel high-throughput packed-bed reactor system. The results indicated that catalytic pathway mechanisms were affected by the substrate. An optimal supporting oxide may thus contribute to the engineering and intensification of unconventional feedstock processing, e.g., CO2, as well as the design of emerging catalysis routes. The produced synthesis gas may be readily used for basic chemical platforms, such as methanol. [ABSTRACT FROM AUTHOR]

We report on synthesis and characterization of a novel group of compounds based on copper, gadolinium, and calcium. Cu-Ca and Cu-Gd binaries were previously studied while Ca and Gd are known to be immiscible themselves. The effects of substituting Gd with Ca in Cu5Gd1-xCax compounds (0≤x≤1) were studied by investigating the phase stability and crystal structure of the resulting new compounds in five specimens with x = 0, 0.33, 0.50, 0.66, and 1, respectively. The samples produced by melt-spinning had hexagonal P6/mmm structure, irrespective of Ca amount (x), where lattice parameters varied with x linearly. This is an indication of good solid solubility under the preparation conditions. A slower cooling upon arc-melting caused the liquid phase separation into Cu4.5Gd and Cu-Ca compounds. Using TEM, rapidly solidified ribbons (Cu5Gd0.5Ca0.5) were investigated and the formation of a homogeneous ternary phase with a nearly nominal stoichiometric composition and minor amounts of Cu-Ca secondary phase was observed. Using DSC and HT XRD, we found that these systems are stable at least up to 400°C. Upon a 16-hour hydrogenation at 1 bar and 300°C, all specimens absorbed about 0.5 wt.% of hydrogen. This caused changes in structure with the formation of pure Cu and H2Gd1-xCax solid solution. [ABSTRACT FROM AUTHOR]

The one-step solvolysis and hydro-treatment of oak, fir and beech sawdust was studied in a slurry reactor using tetralin, phenol and glycerol as solvents and representative heterogeneous catalysts used in the petrochemical industry for hydrogenolysis (the sulfide form of NiMo/Al2O3), hydrogenation (Pd/Al2O3) or fluid catalytic cracking (zeolite Y). Deoxyliquefaction products of cellulose, hemicellulose and lignin were characterised in terms of solvent fractionation, FTIR and diffuse reflectance infrared Fourier transform spectroscopy, elemental analysis and an innovative method for particle size distribution and mean grain size determination by SEM image processing. A new lumped kinetic model was developed according to the reaction mechanisms, which contain wood de-polymerisation, decarbonylation, decarboxylation and demethanation, tar phase hydrodeoxygenation by molecular and in situ generated hydrogen, as well as charring inhibition by free-radical stabilisation hydrogen transfer. [ABSTRACT FROM AUTHOR]

So far, in situ-generated Ni nanoparticles have been reported to be efficient catalysts for tar cracking during wood liquefaction by pyrolysis. Herein, their performance in further bio-oil conversion steps is evaluated. Nanoparticles were generated for the first time from a Ni-containing metal-organic framework, MIL-77, during the hydrotreatment of glycerol-solvolyzed lignocellulosic (LC) biomass. Reactions were conducted at 300 °C and the H2 pressure was 8 MPa in a slurry reactor. The catalytic activity and selectivity of the deoxygenation and hydrocracking reactions for real biomass-derived feedstock using in situ-generated nanoparticles was compared with Ni nanoparticles dispersed on a silica-alumina support (commercial Ni/SiO2-Al2O3 catalyst). The mass activity of the in situ-generated nanoparticles for hydrogenolysis was more than ten times higher in comparison to their commercial analogues, and their potential for the use in LC biorefinery is discussed. [ABSTRACT FROM AUTHOR]

Photocatalytic phenol dissociation was studied in a microreactor, with a TiO2 layer immobilized on the reactor inner walls. Experiments were conducted for various residence times, initial concentrations, pH values, and UV light irradiation intensities. The intermediates and products (catechol, hydroquinone, and resorcinol) were quantitatively investigated to determine the predominant reaction pathways for the investigated anatase catalyst. A three-dimensional mathematical model was used to simulate the heterogeneous photocatalysis reaction conditions with Langmuir-Hinshelwood mechanism, considering the adsorption/desorption thermodynamic equilibria, and for kinetic parameter estimation via regression analysis. The effectiveness factor, Thiele modulus, and the correction function were calculated to determine the pore diffusion effects. The value of pH had the dramatic effect of lowering the reaction rate due to the competitive adsorption of hydroxide ions and protons on the catalyst surface. A phenol conversion of 79.5% was achieved at the residence time of 7.22 min, but without total mineralization. © 2014 American Institute of Chemical Engineers AIChE J, 61: 572-581, 2015 [ABSTRACT FROM AUTHOR]

Isolation step of vancomycin, a glycopeptide antibiotic, is usually done from fermentation broth filtrate, while its adsorption directly from the whole broth could rationalize the process. The equilibrium and kinetics of vancomycin adsorption from broth supernatant, diluted and whole broth on polymeric adsorbent was studied in this work. Experimental equilibrium data was correlated with Sips, Langmuir, Freundlich, and linear adsorption isotherms. Agreement between measured and regressed data for the first three mentioned models did not vary much and was relatively high. The maximum adsorbed amount for supernatant was higher than for fermentation broths because mycelium particles blocked adsorbent surface. Liquid film mass transfer studies showed that external mass transfer resistance could have been neglected. Diffusion of vancomycin inside adsorbent particles was acknowledged using a nonstructural, homogenous surface diffusion and bidisperse pore models. Model simulations indicated that kinetics of the process could be improved by using smaller adsorbent particles. © 2011 American Institute of Chemical Engineers AIChE J, 2012 [ABSTRACT FROM AUTHOR]

The article discusses peroxide crosslinking, examining the crosslinking of various elastomers with several organic peroxides. The peroxides used in the research include dicumyl peroxide (DCP), τ-butyl peroxide (TBP), and di(2-τ-butylperoxyisopropyl) benzene (DTBPIB). Other topics include developing a general description of the governing chemistry, a fundamental kinetic model for the peroxide crosslinking, and a population balance method that acknowledges that nature of the elastomer backbone and network.

The article discusses a study which examined the morphology of blends of three different coagents on a reinforcing substrate with dicumyl peroxide and hydrogenated acrylonitrile butadiene elastomer after processing. Results of the study showed that there was microphase and nanophase evolution during processing in the case of zinc dimethacrylate (ZDMA) and trimethylolpropane trimethacrylate (TMPTMA). The study has also observed a reinforcing effect of ZDMA and TMPTMA during the glass-transition.