CuZnAl catalysts were prepared by precursor complete liquid phase-pyrolysis.The impact of the H2O/Al(i-OPr)3 molar ratio on the catalyst's structural properties,surface nature,and performance in catalyzing CO2 hydrogenation to methanol was systematically evaluated.The role of H2O/Al(i-OPr)3 molar ratio in modulating the crystal phase composition,specific surface area,reducibility,surface acidity-basicity,and active site distribution of the catalysts was analyzed by XRD,N2 adsorption-desorption,H2-TPR,CO2-TPD,XPS,and In-situ DRIFTS.The results show that H2O/Al(i-OPr)3 molar ratio significantly affects the dispersion and crystallite size of Cu species,thereby modulating the activity and selectivity of the catalysts.Among them,the CZA-103 catalyst achieved a CO2 conversion of approximately 12%and a methanol selectivity of around 40%at 250 ℃,3.0 MPa,and GHSV of 4000 h-1,with no deactivation observed after more than 120 h on stream,exhibiting the optimal catalytic performance.In-situ DRIFTS analysis indicates that the reaction mainly proceeds via the formate(HCOO*)intermediate pathway.This work reveals how the H2O/Al(i-OPr)3 molar ratio governs the structural regulation of CuZnAl catalysts,thereby furnishing experimental support and theoretical direction for the rational design and optimization of catalysts for CO2 hydrogenation to methanol.
Isosorbide and 1,4-anhydroerythritol,as high-value-added compounds obtained from the dehydration and cyclization of biomass-derived sugar alcohols,are widely used in chemical,medical,and biological applications with considerable market demand.The production of such value-added products from non-food sugars via green catalytic dehydration routes is of significant importance.This review summarizes recent advances in catalytic systems and industrial applications for the dehydration-cyclization of non-food-based sorbitol and erythritol.Furthermore,the basic research and industrial implementation of relevant polyol dehydration-cyclization catalytic systems in recent years are discussed,aiming to provide scientific guidance for the development of downstream high-value-added products from non-food biomass polyols.
Proton-conducting solid oxide electrolysis cells(H-SOECs)offer a promising route for green hydrogen production due to their ability to operate efficiently at an intermediate temperature range(400-600 ℃)and produce dry hydrogen directly.However,their large-scale deployment faces synergistic challenges across three interconnected levels:materials(trade-off between high proton conductivity and chemical stability),interfaces(sluggish proton-coupled electron transfer kinetics and surface segregation-induced degradation at triple-phase boundaries),and systems(non-uniform distributions of thermal,electrical,flow,and chemical potential fields that accelerate material aging and interfacial failure under multi-physics coupling).From the perspective of"materials-interfaces-systems"synergy,this review provides a systematic overview of recent advances in H-SOECs.It first outlines the fundamental principles and the synergistic framework,emphasizing the interplay among the three levels.It then analyzes the design strategies for electrolytes,hydrogen electrodes,and air electrodes,highlighting cutting-edge approaches such as Zr/Ce solid solutions,Hf doping,in situ exsolution of metal nanoparticles,and triple-conducting oxides.The mechanisms of energy and mass transport at triple-phase boundaries,along with degradation mechanisms,are then discussed,followed by a summary of interfacial engineering strategies including nanostructuring,ordering,and functionalization.Moving from single cells to stack scales,the review examines system-level optimization under multi-physics coupling and strategies for thermal and flow management.Finally,pathways toward cross-scale integrated optimization are proposed,and future research directions are outlined.
To address the demand for efficient abatement of volatile organic compounds(VOCs)in oilfield associated gas,a series of M-Mn bimetallic oxide catalysts incorporating different precursors(Co,Cu,Ce,La,Sm)were synthesized via a redox-precipitation method.The role of various metal components in modulating the phase structure of the Mn-based catalysts was systematically investigated.Toluene,a typical aromatic compound,was employed as the model pollutant to comprehensively evaluate the catalytic activity of the prepared samples and elucidate the reaction mechanism of the optimal catalyst.Among the catalysts,CeMnOx exhibited the best catalytic performance,with an ignition temperature(T10)of 102 ℃ and a 90%conversion temperature(T90)of 168 ℃ for 11265 mg·m-3 toluene degradation,along with excellent CO2 selectivity.Such outstanding performance can be ascribed to the large specific surface area,uniform pore structure,strong synergistic interaction,abundant surface active oxygen species,and appropriate ratio of adsorbed oxygen(Oads)to surface lattice oxygen(Olatt).It is proposed that Oads dominates the reaction at low temperatures through the Langmuir-Hinshelwood mechanism,while Olatt prevails at elevated temperatures via the Mars-van Krevelen mechanism.This study provides both theoretical insights and technical guidance for the thermal catalytic elimination of aromatic VOCs over Mn-based catalysts.
The ultraviolet spectrum and theoretical band indicated that the CoCeOx component exhibited metal-like characteristics,forming a good Schottky junction with CdS.This Schottky junction establishes an interfacial built-in electric field,offering a powerful driving force for the separation and transport of photogenerated carriers.Specifically,under light excitation,the electrons generated by CdS can be rapidly and directionally transferred through the metal-like channels of CoCeOx,while the holes remain in the valence band of CdS,achieving effective spatial separation of electrons and holes,significantly inhibiting the loss of carrier recombination.Meanwhile,the intimate and robust interface between CoCeOx and CdS facilitates efficient charge transfer and simultaneously improves the structural durability of the hybrid catalyst under long-term photocatalytic conditions.Experimental results showed that the optimized CdS/CoCeOx composite material exhibited significantly improved hydrogen production rate and excellent cycling stability in the photocatalytic water decomposition hydrogen production reaction,with no significant performance decline in multiple hydrogen production tests.This study demonstrates a Schottky-junction-based strategy to regulate photogenerated charge behavior.It also offers new insights and experimental foundations for designing efficient,stable composite photocatalysts for solar energy conversion.
