Driven by the growing global energy demand and the pursuit of carbon utilization goals, dry reforming of methane (DRM) has attracted considerable attention for its ability to convert CO2 and CH4 into syngas. Biogas, an eco-friendly product of processes such as anaerobic digestion, is primarily composed of CO2 and CH4 and ideally meets the feedstock requirements for DRM. In practice, biogas is generated via anaerobic digestion of livestock manure and other organic waste, providing a stable and sustainable source for the DRM reaction and thus enabling waste valorization. Supported Ni0 catalysts have become a research focus in this field due to their high catalytic activity and moderate cost. Conventional particulate Ni0 catalysts, however, are prone to carbon coking in fixed-bed applications and are difficult to effectively recover and regenerate after the reaction; thus, they are often being discarded, leading to resource waste and environmental burden. To address these issues, this study has designed a novel metal-sintered fleece catalyst support and developed a corresponding reactor. The effects of the catalyst preparation method, activation conditions, and the support structure on DRM performance have been systematically investigated. The spent Ni-based catalyst could be regenerated via calcination to restore catalytic activity and enable multiple cycles of use, significantly extending the catalyst’s lifespan and offering both economic and environmental benefits. Experimental results have demonstrated that the reactor achieved a conversion rate exceeding 80% with near-complete product selectivity.

Catalytic oxidation of carbon monoxide over copper-Cerium mixed oxide catalysts: Effect of catalyst preparation method

ABSTRACT Bimetallic Co–Ni co‐doped carbon nitride catalysts (CoNi‐CN) were prepared by a simple one‐step thermal condensation method and used for photocatalytic nitrogen fixation. The obtained catalysts were analyzed by various characterization methods and DFT simulations. The results show that the metal is doped in the interstitial position by forming metal‐N coordination bonds. Compared with mono‐metal Ni‐doped g‐C 3 N 4 (graphite carbon nitride), the addition of cobalt reduces the band gap energy and improves the electron–hole separation efficiency. In addition, the introduction of cobalt promotes the activation of nitrogen molecules and accelerates the transfer of electrons from the catalyst to the activated nitrogen molecules through the “Ni–Co–N bridge”. The NH 4 + formation rate of CoNi‐CN is 1.8 mg·L −1 ·h −1 ·g cat −1 , which is 4.5 and 1.5 times higher than that of neat and mono Ni‐doped g‐C 3 N 4 . This study provides a simple and effective catalyst preparation method for nitrogen photofixation.

Chitosan-derived carbon aerogel stabilized Ru nanoparticles: Facile fabrication and application in catalyzing NH3BH3 hydrolytic dehydrogenation

Photoelectrocatalytic (PEC) hydrogen production technology combines the advantages of photocatalysis and electrocatalysis and utilizes solar energy to drive water splitting, which is a technology for sustainable energy systems. However, its low photocatalytic water splitting efficiency results in relatively small hydrogen production. And the cost-effectiveness of PEC water splitting technology and the overall solar energy conversion efficiency to hydrogen remains a great challenge. Metal-organic frameworks (MOFs) are porous materials created through the coordination of metal ions or clusters with organic bridging ligands via ligand bonds. They offer high specific surface areas, abundant metal active sites, large pore volumes, and customizable structures and compositions, making them highly favorable for applications in photoelectrocatalysis. This review discusses the advancements in photoelectrocatalytic hydrogen production technology using metal-organic frameworks (MOFs) and derivatives. It covers the principles of photoelectrocatalysis, preparation methods for MOF catalysts and strategies for performance enhancement. These strategies include improving light absorption, enhancing carrier separation efficiency, and ensuring stability. The paper also discusses the current challenges and future directions of photoelectrocatalytic water splitting technology. Overall, this review offers a thorough theoretical framework and practical insights for researchers in this field.

There are many obstacles to the industrial application of CO2 hydrogenation reduction technology, the most important of which is the high economic cost. The purpose of this study is to explore the interaction mechanism between the active component CuO-ZnO-Al2O3(CZA) and the zeolite carrier Zeolite Socony Mobil-5(ZSM-5), screen the simplified preparation method of catalysts with high catalytic performance, and further promote the industrial application of CO2 hydrogenation reduction technology. In this study, the effects of the gas velocity of the feedstock, the reaction temperature, the content of acidic sites in the carrier, the filling amount of active component, and the mixing mode of the active component and the carrier on catalytic CO2 hydrogenation reduction were investigated. The structure of the catalysts was analyzed by X-ray diffractometer (XRD), Brunauer-Emmett-Teller (BET), Fourier-transform infrared spectroscopy (FTIR), scanning electron microscope (SEM) and transmission electron microscopy (TEM). The catalyst surface properties were analyzed by X-ray photoelectron spectroscopy (XPS), ammonia temperature programmed desorption (NH3-TPD), hydrogen temperature programed reduction (H2-TPR) and other characterization methods. The research found that the grinding treatment led to the insertion of CZA between ZSM-5 zeolite particles in CZA@HZ5-20-GB, which was prepared via grinding both CZA and H-ZSM-5 with an Si/Al ratio of 20, inhibiting the action of strongly acidic sites in the zeolite, resulting in only CO and MeOH in the catalytic products, with no Dimethyl Ether (DME) generation.

Occurrence of elemental exchange in catalytic pyrolysis of poplar sawdust with homologous biochar catalysts doped with nitrogen.

Preparation method of Ni-based high-entropy oxide catalyst and its application in carbon dioxide reforming of methane to prepare syngas

The liquid organic hydrogen carrier (LOHC) technology is a promising route for efficient hydrogen storage, and Ir complexes belong to an important family of homogeneous catalysts applied in this field. We developed and optimized a “2-step” method for the synthesis of complex Cp*Ir(C6H3NF3O)Cl. This complex, designated as T1 in this work, was originally referred to as 2c in ref. [Yamaguchi et al. J. Am. Chem. Soc., 2009, 131, 8410–8412]. The “2-step” method improved the yield of complex T1 and offered a simplified operational process, compared to the previously reported “sodium salt” method. The excellent catalytic activity of T1, synthesized by the “2-step” method was further confirmed. This method was further applied to synthesize other Ir catalysts, T2 and T3. 5-Fluoro-2-hydroxypyridine and 5-nitro-2-hydroxypyridine were assigned to prepare the dehydrogenation catalysts T2 and T3, respectively. Both T2 and T3 effectively catalyzed the dehydrogenation of 2-Me-THQ. Their catalytic activities followed the trend T1 > T2 > T3, highlighting the crucial role of electron-withdrawing ligands in enhancing catalytic performance. In addition, the precursor [Cp*IrHCl]2 (H1) obtained through this “2-step” method, exhibited good performance in 2-Me-Q hydrogenation. H1 and T1 were also successfully applied to the hydrogenation and dehydrogenation of other nitrogen-containing carriers, respectively.

Abstract The sulfur‐tolerant coal‐to‐gas conversion process demonstrates notable advantages in process simplicity and environmentally friendly features. Developing high‐efficiency sulfur‐tolerant methanation catalysts remains critical for advancing this technology. Traditional plasma catalyst preparation methods employ fixed‐bed operations, resulting in uneven catalyst surface properties and scalability concerns. To address these challenges, this study proposes an innovative approach to optimize sulfur‐tolerant methanation catalysts through the implementation of plasma‐fluidized bed reactor technology. The research focuses on sequential plasma treatment and calcination for catalyst preparation, followed by stability evaluation. The catalysts were characterized using N 2 physical adsorption, XRD, TGA, Raman, NH 3 ‐TPD, XPS, and TPR in order to elucidate catalyst properties. The results indicate that the catalysts prepared in the plasma fluidized bed reactor exhibited initial CO conversion of 33.6%. Furthermore, during the 30‐h stability test, the prepared catalysts initially demonstrated good stability, with an observed decrease in activity from 33.6% to 31.7%, representing a 5.7% relative decrease in performance.

This review examines the research progress on non-noble-metal-based catalysts for formaldehyde (HCHO) oxidation at room temperature. It begins with an introduction to the hazards of HCHO as an indoor pollutant and the urgency of its removal, comparing several HCHO removal technologies and highlighting the advantages of room-temperature catalytic oxidation. It delves into the classification, preparation methods, and regulation strategies for non-precious metal catalysts, with a focus on manganese-based, cobalt-based, and other transition metal-based catalysts. The effects of catalyst preparation methods, morphological structure, and specific surface area on catalytic performance are discussed, and the catalytic oxidation mechanisms of HCHO, including the Eley–Rideal, Langmuir–Hinshelwood, and Mars–van Krevelen mechanisms, are analyzed. Finally, the challenges faced by non-precious metal catalysts are summarized, such as issues related to the powder form of catalysts in practical applications, lower catalytic activity at room temperature, and insufficient research in the presence of multiple VOC molecules. Suggestions for future research directions are also provided.

Abstract Energy‐efficient chemical looping‐based oxidative dehydrogenation of ethane (CL‐ODH, C2H6 + 1/2O2 = C2H4 + H2O) was composed of the reduction step of metal oxides by ODH reaction to produce ethylene and successive CO2 activation (oxidation step) on the partially reduced metal oxides to produce CO or by a reverse Boudouard reaction with surface coke precursors (C + CO2 = 2CO). The optimization of preparation methods of FeOx‐TiO2 catalysts was investigated by using hydrothermal (HT), coprecipitation (CP), and impregnation (IM) method, separately. The FeTiOx(HT) catalyst synthesized by hydrothermal method showed the stable preservation of the active FeTiO3 phases on the rutile TiO2 phase with moderate ethylene yield of 4.5% (higher C2H6 conversion of 18.0%), where Fe phases were easily transformed between the metallic Fe0 and oxidized Fe2+ phase during the oxidative C2H6 dehydrogenation (reduction reaction) step and Fe2+ and Fe3+ phase during CO2 activation (oxidation reaction by reverse Boudouard reaction) step after three cyclic CL‐ODH reactions. The larger amount of surface oxygens on the FeTiOx(CP) was responsible for an increased selectivity to COx byproducts of 81.5% compared to the more active and selective FeTiOx(IM) and FeTiOx(HT) due to larger number of electrophilic surface oxygens for facile complete oxidation activity.

Biodiesel, a renewable and environmentally friendly alternative to fossil fuels, has attracted significant attention due to its potential to reduce greenhouse gas emissions. However, high production costs and complex processing remain challenges. Heterogeneous catalysts have shown promise in overcoming these barriers by offering benefits, such as easy separation, reusability, low-cost raw materials, and the ability to reduce reaction times and energy consumption. This review evaluates key classes of heterogeneous catalysts, such as metal oxides, ion exchange resins, and zeolites, and their performance in transesterification and esterification processes. It highlights the importance of catalyst preparation methods, textural properties, including surface area, pore volume, and pore size, activation techniques, and critical operational parameters, like the methanol-to-oil ratio, temperature, time, catalyst loading, and reusability. The analysis reveals that catalysts supported on high surface area materials often achieve higher biodiesel yields, while metal oxides derived from natural sources provide cost-effective and sustainable options. Challenges, such as catalyst deactivation, sensitivity to feedstock composition, and variability in performance, are discussed. Overall, the findings underscore the potential of heterogeneous catalysts to enhance biodiesel production efficiency, although further optimization and standardized evaluation protocols are necessary for their broader industrial application.

Abstract The drive to decarbonize the chemical, oil, and gas industries through use of bio‐derived resources is intensifying. This study focuses on converting lignin‐derived phenolic compounds into cyclohexanol, a precursor for adipic acid production. The alumina hollow fiber supported cobalt catalyst (5Co/AHF@capillary) prepared by capillary action method was found to consist cobalt in both metallic and +δ oxidation states. Initial tests in a batch‐mode reactor showed promising results, with 5Co/AHF@capillary catalyst demonstrating catalytic activity comparable to Ru/Al₂O₃ systems (225 °C, 1 MPa H2, 4 h), achieving ∼86% cyclohexanol yield in guaiacol hydrodeoxygenation reactions. The catalytic system was then adapted for continuous flow reactors under milder conditions (300 °C, 2.5 MPa H2, 18 mL min−1), resulting in 83% guaiacol conversion and 74% cyclohexanol yield. The durability of the catalyst was checked for >80 h and results claim that catalyst was active in yielding consistent results. The roles of catalyst preparation method, hydrogen pressure, solvent, WHSV were thoroughly checked and discussed.

Ruthenium-based catalysts are considered efficient and cost-effective potential alkaline electrolysis water catalysts that exhibit both hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) activities. Therefore, it is crucial to develop straightforward and low-energy synthesis methods for ruthenium-based alloy catalysts. In this study, we present a microwave synthesis approach for rapidly fabricating RuCo alloy supported on copper foam. Microwave heating, with its unique heating method, enables the efficient and rapid synthesis of alloy particles in a very short period of time. The synthesized RuCo/Cu2O/CF demonstrates excellent bifunctional HER and OER activities in alkaline media. Compared to commercial precious metal catalysts, RuCo/Cu2O/CF exhibits lower overpotentials and improved electrocatalytic kinetics, with an overpotential of 43 mV (10 mA cm-2) for HER and a Tafel slope of 37.6 mV dec-1, and an overpotential of 253 mV (10 mA cm-2) for OER, also with a Tafel slope of 189.1 mV dec-1. Moreover, the synthesized RuCo/Cu2O/CF shows remarkable stability. Theoretical calculations indicate that after alloying with Ru, both the water dissociation energy barrier and hydrogen adsorption energy on the Co surface are optimized. In a symmetric dual-electrode system, the RuCo/Cu2O/CF electrolyzer requires only 1.56V to achieve a current density of 10 mA cm-2, outperforming commercial precious metal catalysts while exhibiting excellent long-term stability. These findings reveal a simple, low-energy preparation method for alloy catalysts, providing new insights into the development of water-splitting catalysts.

The effect of catalyst preparation methods on biomass hydrothermal liquefaction: Exploring cleaner and more efficient pathways for catalytic hydrothermal liquefaction of biomass

Effects of the preparation methods of Co3O4 catalysts on catalytic oxidization performance toward o-xylene

A group of CuAl catalysts were synthesized with a Cu/Al molar ratio of 1:1 using different preparation methods: coprecipitation, surfactant assisted coprecipitation, polymeric precursor, and self-combustion and then screened for the selective dehydration of glycerol to acetol. The catalysts were employed in glycerol conversion at the same temperature (227 °C) in two different laboratory-scale systems, the first one at atmospheric pressure (gas phase) and the second one in a pressurized system at 34 absolute bar (liquid phase). The preparation method of the CuAl catalysts influenced the carbon yield to liquids and acetol selectivity. However, the reaction phase had a greater influence than the preparation method of the catalyst. In the gas phase, the carbon yield to liquids reached values above 40% and the carbon selectivity to acetol was higher than 90%. The highest acetol yield, 462.6 mgacetol/gglycerol, was obtained with the CuAl catalyst prepared by the surfactant-assisted coprecipitation method. This study provides a new perspective on catalyst design by highlighting the crucial role of preparation techniques in determining CuAl catalyst performance in the liquid and gas phases.

In this work, we review the latest progress in single atom alloy (SAA) catalysis and its applications to thermo-, photo- and electro-catalytic processes. Part I discusses SAA catalyst preparation methods as well as characterisation techniques.

Abstract The detrimental impacts of nitrogen oxides (NOx) on health and the environment necessitates their selective catalytic reduction. Among many catalysts, Ag/γ‐Al2O3 shows promise for effective NOx reduction. However, its formulation varies in terms of preparation protocols, which influence the structural, morphological, and textural properties of Ag/γ‐Al2O3 catalyst and ultimately impact the catalytic performance. In this work, an inclusive crucial parameter that represents the loading of Ag atoms per given area (nm2) of the catalyst surface—silver surface density (σAg) is introduced and incorporated into a kinetic model in order to account for these catalyst properties influential factors. By mathematically formulating the sensitive rate constants based on σAg, a simplified global kinetic model is developed that successfully validates NOx conversions for large datasets of literature. The proposed model captures experiments covering diverse catalyst preparation methods for Ag/γ‐Al2O3 (impregnation and sol–gel) and Ag loadings (2–6 wt.%). It applies well to various reactor operating conditions, including various inlet feed concentrations, flow rates, space velocities, and catalyst amounts. The developed kinetic model is identified the optimal σAg value to 1.0, which is an important parameter for the catalyst design. The model prediction of NOx conversions reached 99%, and more than 70% NOx conversion is observed over a broader activity temperature window ranging from 350 to 600°C, under the estimated optimal reaction conditions. Therefore, this model, along with its versatile applicability, provides deep insights into catalyst synthesis–structure–activity relationships and delivers practical understandings for improved NOx reduction in exhaust gases in automotive applications.