CuZnAl(CZA)is a classic industrial catalyst widely used for the synthesis of methanol from syngas,but its catalytic performance is not optimal for the hydrogenation of CO_(2) to methanol.Meanwhile,understanding the ca...CuZnAl(CZA)is a classic industrial catalyst widely used for the synthesis of methanol from syngas,but its catalytic performance is not optimal for the hydrogenation of CO_(2) to methanol.Meanwhile,understanding the catalytic mechanism of Cu species in the CZA catalyst remains a great challenge.In this study,we systematically investigated the valence state change of active Cu species in CZA catalyst and their influence on catalytic performance by modifying the catalysts with varying amounts of electron donor K,thus identifying the catalytic function of Cu species with different valence states.H2-TPR,XPS and HR-TEM characterizations reveal that the highly dispersed K species supported on CZA catalysts will inhibit the reduction of CuO,resulting in a small amount of Cu_(2)O active species being produced under reaction conditions thus causing a decrease in catalytic activity.Furthermore,XRD and Cu LMM spectra show that the proportion of Cu^(0) in K-modified CZA catalysts increases with K loading,but a higher proportion of Cu^(0) species on the surface obviously promotes the reverse water gas shift(RWGS)reaction.According to the results of in situ infrared spectroscopy,CZA catalyst follows the reaction pathway mediated by HCOO^(*)in the hydrogenation of CO_(2) to methanol.展开更多
Against the backdrop of escalating global climate change and energy crises,the resource utilization of carbon dioxide(CO_(2)),a major greenhouse gas,has become a crucial pathway for achieving carbon peaking and carbon...Against the backdrop of escalating global climate change and energy crises,the resource utilization of carbon dioxide(CO_(2)),a major greenhouse gas,has become a crucial pathway for achieving carbon peaking and carbon neutrality goals.The hydrogenation of CO_(2)to methanol not only enables carbon sequestration and recycling,but also provides a route to produce high value-added fuels and basic chemical feedstocks,holding significant environmental and economic potential.However,this conversion process is thermodynamically and kinetically limited,and traditional catalyst systems(e.g.,Cu/ZnO/Al_(2)O_(3))exhibit inadequate activity,selectivity,and stability under mild conditions.Therefore,the development of novel high-performance catalysts with precisely tunable structures and functionalities is imperative.Metal-organic frameworks(MOFs),as crystalline porous materials with high surface area,tunable pore structures,and diverse metal-ligand compositions,have the great potential in CO_(2)hydrogenation catalysis.Their structural design flexibility allows for the construction of well-dispersed active sites,tailored electronic environments,and enhanced metal-support interactions.This review systematically summarizes the recent advances in MOF-based and MOF-derived catalysts for CO_(2)hydrogenation to methanol,focusing on four design strategies:(1)spatial confinement and in situ construction,(2)defect engineering and ion-exchange,(3)bimetallic synergy and hybrid structure design,and(4)MOF-derived nanomaterial synthesis.These approaches significantly improve CO_(2)conversion and methanol selectivity by optimizing metal dispersion,interfacial structures,and reaction pathways.The reaction mechanism is further explored by focusing on the three main reaction pathways:the formate pathway(HCOO*),the RWGS(Reverse Water Gas Shift reaction)+CO*hydrogenation pathway,and the trans-COOH pathway.In situ spectroscopic studies and density functional theory(DFT)calculations elucidate the formation and transformation of key intermediates,as well as the roles of active sites,metal-support interfaces,oxygen vacancies,and promoters.Additionally,representative catalytic performance data for MOFbased systems are compiled and compared,demonstrating their advantages over traditional catalysts in terms of CO_(2)conversion,methanol selectivity,and space-time yield.Future perspectives for MOF-based CO_(2)hydrogenation catalysts will prioritize two main directions:structural design and mechanistic understanding.The precise construction of active sites through multi-metallic synergy,defect engineering,and interfacial electronic modulation should be made to enhance catalyst selectivity and stability.In addition,advanced in situ characterization techniques combined with theoretical modeling are essential to unravel the detailed reaction mechanisms and intermediate behaviors,thereby guiding rational catalyst design.Moreover,to enable industrial application,challenges related to thermal/hydrothermal stability,catalyst recyclability,and cost-effective large-scale synthesis must be addressed.The development of green,scalable preparation methods and the integration of MOF catalysts into practical reaction systems(e.g.,flow reactors)will be crucial for bridging the gap between laboratory research and commercial deployment.Ultimately,multi-scale structure-performance optimization and catalytic system integration will be vital for accelerating the industrialization of MOF-based CO_(2)-to-methanol technologies.展开更多
Catalytic CO_(2)-to-methanol conversion presents a synergistic approach for concurrent greenhouse gas abatement and sustainable energy carrier synthesis.Single-atom catalysts(SACs)with maximized atomic utilization,tai...Catalytic CO_(2)-to-methanol conversion presents a synergistic approach for concurrent greenhouse gas abatement and sustainable energy carrier synthesis.Single-atom catalysts(SACs)with maximized atomic utilization,tailored electronic configurations and unique metal-support interactions,exhibit superior performance in CO_(2) activation and methanol synthesis.This review systematically compares reaction mechanisms and pathways across thermal,photocatalytic and electrocatalytic systems,emphasizing structure-activity relationships governed by active sites,coordination microenvironments and support functionalities.Through case studies of representative SACs,we elucidate how metal-support synergies dictate intermediate binding energetics and methanol selectivity.A critical analysis of reaction parameters(e.g.,temperature,pressure)reveals condition-dependent catalytic behaviors in thermal system,with fewer studies in photo/electrocatalytic systems identified as key knowledge gaps.While thermal catalysis achieves industrially viable methanol yields,the scalability is constrained by energy-intensive operation and catalyst sintering.Conversely,photo/electrocatalytic routes offer renewable energy integration but suffer from inefficient charge dynamics and mass transport limitations.To address the challenges,we propose strategic research priorities on precise design of active sites,synergy of multiple technological pathways,development of intelligent catalytic systems and diverse CO_(2) feedstock compatibility.These insights establish a framework for developing next-generation SACs,offering both theoretical foundations and technological blueprints for developing carbon-negative catalytic technologies.展开更多
The breaking of the symmetric electronic distribution of single-atom catalysts is effective in improving the intrinsic activity.However,traditional modification strategies can only disrupt the electronic distribution ...The breaking of the symmetric electronic distribution of single-atom catalysts is effective in improving the intrinsic activity.However,traditional modification strategies can only disrupt the electronic distribution in one dimension,resulting in limited regulation of electronic structure.Herein,we report a multidimensional coordination strategy to significantly break the symmetrical electron distribution of the metal single site to achieve highly efficient electrochemical CO_(2) reduction reaction(CO_(2) RR).Ni singleatom sites decorated with planar P and axial Cl atoms are successfully constructed on carbon support(Ni-NPCl-C).Ni-NPCl-C affords CO Faraday efficiency over 90%in a wide potential window range from-0.5 to-1.2 V and an ultrahigh turnover frequency of 1.17×10^(5)h^(-1),much superior to its counterparts with single-dimensional coordination.Ni-NPCl-C can be further applied as a bifunctional catalyst to construct a rechargeable Zn-CO_(2) battery.Spectroscopic characterizations and theoretical calculations demonstrate that the dual adjustments with axial Cl and planar P can synergistically disrupt the electron distribution in two dimensions to increase electrons around Ni sites with the upshift of the d-band center,thereby facilitating the formation of*COOH intermediates and improving the CO_(2) RR performance.展开更多
Using photoelectrocatalytic CO_(2) reduction reaction(CO_(2)RR)to produce valuable fuels is a fascinating way to alleviate environmental issues and energy crises.Bismuth-based(Bi-based)catalysts have attracted widespr...Using photoelectrocatalytic CO_(2) reduction reaction(CO_(2)RR)to produce valuable fuels is a fascinating way to alleviate environmental issues and energy crises.Bismuth-based(Bi-based)catalysts have attracted widespread attention for CO_(2)RR due to their high catalytic activity,selectivity,excellent stability,and low cost.However,they still need to be further improved to meet the needs of industrial applications.This review article comprehensively summarizes the recent advances in regulation strategies of Bi-based catalysts and can be divided into six categories:(1)defect engineering,(2)atomic doping engineering,(3)organic framework engineering,(4)inorganic heterojunction engineering,(5)crystal face engineering,and(6)alloying and polarization engineering.Meanwhile,the corresponding catalytic mechanisms of each regulation strategy will also be discussed in detail,aiming to enable researchers to understand the structure-property relationship of the improved Bibased catalysts fundamentally.Finally,the challenges and future opportunities of the Bi-based catalysts in the photoelectrocatalytic CO_(2)RR application field will also be featured from the perspectives of the(1)combination or synergy of multiple regulatory strategies,(2)revealing formation mechanism and realizing controllable synthesis,and(3)in situ multiscale investigation of activation pathways and uncovering the catalytic mechanisms.On the one hand,through the comparative analysis and mechanism explanation of the six major regulatory strategies,a multidimensional knowledge framework of the structure-activity relationship of Bi-based catalysts can be constructed for researchers,which not only deepens the atomic-level understanding of catalytic active sites,charge transport paths,and the adsorption behavior of intermediate products,but also provides theoretical guiding principles for the controllable design of new catalysts;on the other hand,the promising collaborative regulation strategies,controllable synthetic paths,and the in situ multiscale characterization techniques presented in this work provides a paradigm reference for shortening the research and development cycle of high-performance catalysts,conducive to facilitating the transition of photoelectrocatalytic CO_(2)RR technology from the laboratory routes to industrial application.展开更多
Elucidating the active site formation mechanism of bismuth(Bi)-based catalysts in electrochemical CO_(2)reduction remains challenging for achieving high activity,selectivity,and long-term stability.Here we confirm thr...Elucidating the active site formation mechanism of bismuth(Bi)-based catalysts in electrochemical CO_(2)reduction remains challenging for achieving high activity,selectivity,and long-term stability.Here we confirm through experimental results that Bi-based catalysts containing halogen ions(I^(-),Cl^(-),Br^(-))and SO_(4)^(2-)maintain the system stability,keeping Faraday efficiency of formic acid above90%in the current range of 50-800 mA cm^(-2).In contrast,anions containing S^(2-)and NO_(3)^(-)in the electrolyte can be reduced to produce by-products.These anions and their by-products could poison the active center,leading to increased side reactions and thus significantly reducing the Faraday efficiency of formic acid.The combination of non-in situ and in situ characterization results revealed that the Bi-based catalysts all underwent the transition from the initial state to the Bi/Bi_(2)O_(2)CO_(3)(BOC)intermediate state in high-concentration KHCO_(3) solution,and the different anions could selectively modulate the degree of exposure of specific crystalline surfaces of BOC.At the late stage of the reaction,BOC was completely converted to metal Bi and became the real active center.Combined with in situ IR and DFT calculations,it is further verified that^(*)OCHO is the key intermediate on the metallic Bi surface,which is most favorable for formic acid formation.This study reveals the key mechanism by which anions affect the formation of active sites via modulating the catalyst reconstruction process,which provides an important theoretical basis for the design and optimization of test conditions of Bi-based catalysts.展开更多
To promote CO_(2)redox kinetics on the cathode of hybrid sodium-carbon dioxide(Na-CO_(2))batteries,hollow cubic CuS nanoboxes were encapsulated in polypyrrole and polydopamine by in situ polymerization of pyrrole and ...To promote CO_(2)redox kinetics on the cathode of hybrid sodium-carbon dioxide(Na-CO_(2))batteries,hollow cubic CuS nanoboxes were encapsulated in polypyrrole and polydopamine by in situ polymerization of pyrrole and dopamine monomers,respectively,and coupled with high-temperature heat treatment to obtain nitrogen-carbon encapsulated Cu_(x)S@NC_(PPy)and Cu_(x)S@NCPDA catalysts.The results show that the encapsulation of nitrogen-doped carbon not only increases the specific surface area and improves the electron affinity but also promotes the synergistic interaction between the CuS-based active species and the defect carbon,thus providing abundant active sites for CO_(2)conversion.The electrochemical performances of the carbon-coated modified samples were all improved,especially the hybrid Na-CO_(2)battery based on Cu_(x)S@NC_(PPy),which showed a low voltage gap of 0.74 V at 0.1 mA/cm^(2)and a high power density of 3.42 mW/cm^(2).展开更多
Electrocatalytic carbon dioxide reduction is a crucial method for addressing energy issues and achieving carbon neutrality.Doping of Cu catalysts represents an effective approach to regulate electrocatalytic carbon di...Electrocatalytic carbon dioxide reduction is a crucial method for addressing energy issues and achieving carbon neutrality.Doping of Cu catalysts represents an effective approach to regulate electrocatalytic carbon dioxide reduction.This review article summarizes the research progress on improving the performance of Cu-based material electrocatalysts through doping regulation.The background,fundamental research,evaluation parameters,and methods for catalyst design,along with their influencing factors,are introduced.Emphasis is placed on the impact of doping with different elements(such as noble metals,transition metals,main-group metals,non-metals,etc.)on the performance of Cu-based catalysts,including the mechanisms for enhancing activity,selectivity,and stability.In-situ characterization techniques have revealed the structural evolution and catalytic mechanisms during the doping process.Mechanistic studies,leveraging the ever-advancing computational capabilities and high-throughput methods,have given rise to typical computational descriptors like volcano plots,free-energy diagrams,and machine-learning-based approaches.These descriptors have become key tools for screening high-efficiency catalysts in various application scenarios of the electrochemical carbon dioxide reduction reaction(CO_(2)RR).This article comprehensively summarizes the current research achievements and looks ahead to the future,indicating that strengthening the combination of theory and experiment and exploring industrial applications are the future research directions,aiming to provide a comprehensive reference for the development of highly efficient doped Cu-based electrocatalysts.展开更多
Large-scale CO_(2)emissions have exacerbated the greenhouse effect,reinforcing the critical need for efficient CO_(2)mitigation methods.Plasma-catalytic technology enables CO_(2)conversion under mild conditions,especi...Large-scale CO_(2)emissions have exacerbated the greenhouse effect,reinforcing the critical need for efficient CO_(2)mitigation methods.Plasma-catalytic technology enables CO_(2)conversion under mild conditions,especially for CO_(2)methanation(the Sabatier reaction),which has attracted significant attention due to its economic benefits and the potential for safe energy transportation via existing natural gas pipelines.The development of high-performance CO_(2)methanation catalysts remains an ongoing and long-term objective,and there is a lack of adequate in-situ characterization techniques to investigate the mechanisms.This study focuses on the Ni/La_(2)O_(3)(LN)catalyst and introduces two CO_(2)activation strategies through F and Na modifications:the Ni-Ov-Ni site activation with electron transfer from Ni0 under low-power conditions and basic site activation under high-power conditions.The LN-NaF catalysts enhance CO_(2)methanation activity across the entire power range compared to LN,achieving a CO_(2)conversion of 86.3%and CH4 selectivity of 99.4%.Additionally,LN-F(h)reaches a CH4 yield 4.15 times higher than that of LN at low power.Furthermore,in-situ diffuse reflectance infrared Fourier transform(DRIFT)spectroscopy with a self-made reactor are performed under plasma-catalytic conditions to reveal the CO_(2)adsorption and conversion mechanisms,indicating that different dopants(F,Na,and NaF)exhibit promoting effects on different intermediates,resulting in variations in CO_(2)methanation activity.This study provides valuable insights for improving catalyst performance and a thorough comprehension of mechanisms in CO_(2)methanation.展开更多
Developing green and efficient methods to acquire lignocellulose-based chemicals with high added value is beneficial for facilitating green chemistry and sustainable development.The goal of this study is to demonstrat...Developing green and efficient methods to acquire lignocellulose-based chemicals with high added value is beneficial for facilitating green chemistry and sustainable development.The goal of this study is to demonstrate that bio-based benzaldehyde,a noteworthy high-value chemical,is able to be directionally prepared from lignocellulosic biomass.This new control-lable transformation was materialized by uniting catalytic-pyrolysis of lignocellulose to toluene intermediate and catalytic oxidation of toluene intermediate to bio-based benzalde-hyde.This work also developed a highly active magnetic catalyst(CoFe_(2)O_(4)@Biochar(HTR)),achieving 77.1%benzaldehyde selectivity and 46.7%benzaldehyde yield using this catalyst.It was found that introducing the biochar carrier into the cobalt iron composite metal oxide cat-alyst enhanced hydroxyl radical formation and bio-based benzaldehyde synthesis.Based on catalyst characterizations and hydroxyl radical analysis,potential reaction mechanism for bio-based benzaldehyde synthesis was proposed.This strategy may provide a beneficial pathway for developing high-value bio-based chemical(benzaldehyde)using renewable lignocellulosic biomass.展开更多
Catalytic activity and hydrothermal stability are both crucial for the application of the selective catalytic reduction of NO_(x)with NH_(3)(NH_(3)-SCR)catalyst in diesel vehicles.In this study,a tin(Sn)-modified Ce-N...Catalytic activity and hydrothermal stability are both crucial for the application of the selective catalytic reduction of NO_(x)with NH_(3)(NH_(3)-SCR)catalyst in diesel vehicles.In this study,a tin(Sn)-modified Ce-Nb mixed-oxide catalyst was synthesized as an NH_(3)-SCR catalyst for NO_(x)emission control.After the intro-duction of Sn,both the NH_(3)-SCR activity and the hydrothermal stability of the catalyst were remarkably promoted.Even after hydrothermal aging at 1000℃,the developed Ce_(1)Sn_(2)Nb_(1)O_(x)catalyst achieved more than 90%NO_(x)conversion at 325-500℃.Various methods,including N2-physisorption,X-ray diffraction,in-situ high-temperature X-ray diffraction,high-resolution transmission electron microscopy,X-ray pho-toelectron spectroscopy,X-ray absorption fine-structure spectroscopy,temperature-programmed reduc-tion of hydrogen,temperature-programmed desorption of ammonia,and density functional theory calculations were used to investigate the promotional effects induced by the Sn species.The characteri-zation results showed that the addition of Sn not only promoted the formation of the Ce-Nb active phase but also improved its thermal stability,contributing to the excellent NH_(3)-SCR performance and hydrothermal stability.This study provides an excellent sintering-resistance catalyst for the application of diesel engine NO_(x)emission control.展开更多
Ethanol steam reforming(ESR)represents a promising route for sustainable hydrogen production,leveraging the high hydrogen content,renewability,and logistical advantages of ethanol.Although Ni-based catalysts are leadi...Ethanol steam reforming(ESR)represents a promising route for sustainable hydrogen production,leveraging the high hydrogen content,renewability,and logistical advantages of ethanol.Although Ni-based catalysts are leading non-noble candidates for ESR,their practical deployment is hindered by compromised H_(2) production efficiency and rapid deactivation.In this work,we combined catalyst synthesis,kinetic analysis,and mechanistic investigation to elucidate the effectsof Ni particle size(3-9 nm)on ESR performance of Ni/CeO_(2) catalysts.These Ni/CeO_(2) catalysts were prepared via a citric acid-assisted coprecipitation method,and systematically characterized using complementary techniques,including high-resolution transmission electron microscopy(HRTEM),in situ X-ray photoelectron spectroscopy(XPS),hydrogen temperature-programmed reduction(H_(2)-TPR),Raman spectroscopy,O_(2)/CO chemisorption,and temperature-programmed surface reaction(TPSR)analyses.Mechanistic study revealed that ethanol dehydrogenation to acetaldehyde is the rate-determining step,defining the intrinsic activity of Ni sites,whereas C-C bond cleavage governs H_(2) selectivity in ESR.At smaller Ni sizes(e.g.,3.1 nm),larger CeO_(2) surface was exposed,which promoted acetaldehyde condensation to acetone,and consequently reduced H_(2) production efficiency.The Ni/CeO_(2) catalyst with~5 nm of Ni particles afforded the highest H_(2) yield(66.3%)and outstanding stability by balancing dehydrogenation activity,H_(2) selectivity,and coking resistance.Conversely,larger Ni particles(>6 nm)facilitated methanation reaction and catalyst deactivation.This work reconciles prior inconsistencies in the Ni size effects on ESR and provides guidance for the design of efficient and durable Ni-based catalysts for H_(2) production.展开更多
To develop efficient catalysts for ambient carbon monoxide(CO)oxidation is significant for indoor air purification and also for many industrial applications.In this work,the catalytic activity for CO oxidation were en...To develop efficient catalysts for ambient carbon monoxide(CO)oxidation is significant for indoor air purification and also for many industrial applications.In this work,the catalytic activity for CO oxidation were enhanced by tuning the metal-support interaction of Ru/CeO_(2)catalysts.A series of Ru/CeO_(2)catalysts were synthesized by an impregnation method with calcination at 100,200,400 and 600℃,respectively,to regulate the Ru-CeO_(2)interaction.We discovered that low temperature calcination(100℃)induced more Ru-O-Ce bonds and stronger Ru-CeO_(2)interaction,while high temperature calcination(≥400℃)caused the agglomeration of Ru species with more Ru-O-Ru bonds and weaker Ru-CeO_(2)interaction,resulting in the lower redox capacity of these catalysts,as well as lower catalytic activity for CO oxidation.Only calcination at moderate 200℃ can induce the moderate interaction between Ru species and CeO_(2)support,which can keep the high dispersion of RuO_(x)species with the high redox capacity,thus leading to complete elimination of 500 ppm CO at room temperature on Ru/Ce-200 catalyst.展开更多
Heterogeneous precious metal catalysts are prone to agglomeration during preparation,requiring high usage with consequently high costs.Maximizing the efficiency of precious-metal utilization is of great significance i...Heterogeneous precious metal catalysts are prone to agglomeration during preparation,requiring high usage with consequently high costs.Maximizing the efficiency of precious-metal utilization is of great significance in the design of supported precious metal catalysts.Herein,2,2'-bipyridyl-5,5'-dicarboxylic acid was used as the ligand in constructing the UiO-67-Ce-BPyDC framework with Ce^(4+)coordination.This framework enables precise adsorption and coordination of Pd2+at the nitrogen sites of pyridine,promoting high dispersion of the Pd species at a single site,thereby facilitating controlled palladium loading.This precursor was used to fabricate supported Pd-based catalysts on CeO_(2)(Pd-N/CeO_(2)-P)via pyrolysis.Notably,because the Pd species are homogeneously distributed on CeO_(2)with strong interactions,Pd-N/CeO_(2)-P exhibits remarkable efficiency in cleaving the C-O bonds of diphenyl ether(DPE)to produce cyclohexanol,with a selectivity of 72.1%.The origin of the high selectivity of cyclohexanol is further elucidated using theoretical calculations;that is,DPE undergoes not only hydrogenolysis on Pd-N/CeO_(2)-P,but also hydrolysis to produce more cyclohexanol.This study not only demonstrates a successful strategy for designing highly dispersed metal catalysts,but also underscores the importance of such tailored catalysts in the advancement of sustainable lignin depolymerization technologies.展开更多
The Co/CeO2 catalysts promoted with Ba or K were prepared to study the effect of promoter on the catalytic performance of ammonia synthesis. The results show that the presence of Ba or K promoter changes the propertie...The Co/CeO2 catalysts promoted with Ba or K were prepared to study the effect of promoter on the catalytic performance of ammonia synthesis. The results show that the presence of Ba or K promoter changes the properties of CeO2-supported Co catalysts including the surface area, the crystallite size and the morphology of CeO2, the reduction degree of cobalt species and the adsorption performance of hydrogen and nitrogen. As a consequence, the samples promoted with an appropriate amount of Ba show higher ammonia synthesis rates, while the catalysts with high Ba loading or K promoter all exhibit low catalytic activities.展开更多
Pt/Ni catalysts modified with CeO2 nanoparticles were prepared by simple composite electrodeposition of Ni and CeO2,and spontaneous Ni partial replacement by Pt processes.The as-prepared CeO2-modified Pt/Ni catalysts ...Pt/Ni catalysts modified with CeO2 nanoparticles were prepared by simple composite electrodeposition of Ni and CeO2,and spontaneous Ni partial replacement by Pt processes.The as-prepared CeO2-modified Pt/Ni catalysts showed enhanced catalytic performance for ethanol electro-oxidation compared with pure Pt/Ni,and acetate species were proposed to be the main products of the oxidation when using these catalysts.The content of CeO2 in the as-prepared catalysts influenced their catalytic activity,with Pt/NiCe2（obtained from an electrolyte containing 100 mg/L CeO2 nanoparticles） exhibiting higher activity and relatively better stability in ethanol electro-oxidation.This was mainly due to the oxygen storage capacity of CeO2,the interaction between Pt and CeO2/Ni,and the relatively small contact and charge transfer resistances.The results of this work thus suggest that electrocatalysts with low price and high activity can be rationally designed and produced by a simple route for use in direct ethanol fuel cells.展开更多
CO2 selective reduction to CO with H2 over a CeO2-supported nano-Au catalyst at atmospheric pres- sure was investigated. A high CO2 conversion, approaching the thermodynamic equilibrium value, and nearly 100% CO selec...CO2 selective reduction to CO with H2 over a CeO2-supported nano-Au catalyst at atmospheric pres- sure was investigated. A high CO2 conversion, approaching the thermodynamic equilibrium value, and nearly 100% CO selectivity were obtained. The surface formate intermediates generated during the reverse water-gas shift reaction at 400 ℃ were identified using in situ diffuse-reflectance infra- red Fourier-transform spectroscopy. The formate consumption to give CO and H20, determined using mass spectrometry, indicated that the reaction proceeded via an associative formate mecha- nism; this contributes to the high Au/CeO2 catalytic activity at low temperatures.展开更多
基金Supported by the National Key Research and Development Program of China(2022YFB4101800)the National Natural Science Foundation of China(22172032,U22A20431)。
文摘CuZnAl(CZA)is a classic industrial catalyst widely used for the synthesis of methanol from syngas,but its catalytic performance is not optimal for the hydrogenation of CO_(2) to methanol.Meanwhile,understanding the catalytic mechanism of Cu species in the CZA catalyst remains a great challenge.In this study,we systematically investigated the valence state change of active Cu species in CZA catalyst and their influence on catalytic performance by modifying the catalysts with varying amounts of electron donor K,thus identifying the catalytic function of Cu species with different valence states.H2-TPR,XPS and HR-TEM characterizations reveal that the highly dispersed K species supported on CZA catalysts will inhibit the reduction of CuO,resulting in a small amount of Cu_(2)O active species being produced under reaction conditions thus causing a decrease in catalytic activity.Furthermore,XRD and Cu LMM spectra show that the proportion of Cu^(0) in K-modified CZA catalysts increases with K loading,but a higher proportion of Cu^(0) species on the surface obviously promotes the reverse water gas shift(RWGS)reaction.According to the results of in situ infrared spectroscopy,CZA catalyst follows the reaction pathway mediated by HCOO^(*)in the hydrogenation of CO_(2) to methanol.
基金Supported by the National Key Research and Development Program of China(2023YFB4104500,2023YFB4104502)the National Natural Science Foundation of China(22138013)the Taishan Scholar Project(ts201712020).
文摘Against the backdrop of escalating global climate change and energy crises,the resource utilization of carbon dioxide(CO_(2)),a major greenhouse gas,has become a crucial pathway for achieving carbon peaking and carbon neutrality goals.The hydrogenation of CO_(2)to methanol not only enables carbon sequestration and recycling,but also provides a route to produce high value-added fuels and basic chemical feedstocks,holding significant environmental and economic potential.However,this conversion process is thermodynamically and kinetically limited,and traditional catalyst systems(e.g.,Cu/ZnO/Al_(2)O_(3))exhibit inadequate activity,selectivity,and stability under mild conditions.Therefore,the development of novel high-performance catalysts with precisely tunable structures and functionalities is imperative.Metal-organic frameworks(MOFs),as crystalline porous materials with high surface area,tunable pore structures,and diverse metal-ligand compositions,have the great potential in CO_(2)hydrogenation catalysis.Their structural design flexibility allows for the construction of well-dispersed active sites,tailored electronic environments,and enhanced metal-support interactions.This review systematically summarizes the recent advances in MOF-based and MOF-derived catalysts for CO_(2)hydrogenation to methanol,focusing on four design strategies:(1)spatial confinement and in situ construction,(2)defect engineering and ion-exchange,(3)bimetallic synergy and hybrid structure design,and(4)MOF-derived nanomaterial synthesis.These approaches significantly improve CO_(2)conversion and methanol selectivity by optimizing metal dispersion,interfacial structures,and reaction pathways.The reaction mechanism is further explored by focusing on the three main reaction pathways:the formate pathway(HCOO*),the RWGS(Reverse Water Gas Shift reaction)+CO*hydrogenation pathway,and the trans-COOH pathway.In situ spectroscopic studies and density functional theory(DFT)calculations elucidate the formation and transformation of key intermediates,as well as the roles of active sites,metal-support interfaces,oxygen vacancies,and promoters.Additionally,representative catalytic performance data for MOFbased systems are compiled and compared,demonstrating their advantages over traditional catalysts in terms of CO_(2)conversion,methanol selectivity,and space-time yield.Future perspectives for MOF-based CO_(2)hydrogenation catalysts will prioritize two main directions:structural design and mechanistic understanding.The precise construction of active sites through multi-metallic synergy,defect engineering,and interfacial electronic modulation should be made to enhance catalyst selectivity and stability.In addition,advanced in situ characterization techniques combined with theoretical modeling are essential to unravel the detailed reaction mechanisms and intermediate behaviors,thereby guiding rational catalyst design.Moreover,to enable industrial application,challenges related to thermal/hydrothermal stability,catalyst recyclability,and cost-effective large-scale synthesis must be addressed.The development of green,scalable preparation methods and the integration of MOF catalysts into practical reaction systems(e.g.,flow reactors)will be crucial for bridging the gap between laboratory research and commercial deployment.Ultimately,multi-scale structure-performance optimization and catalytic system integration will be vital for accelerating the industrialization of MOF-based CO_(2)-to-methanol technologies.
基金supported by the National Natural Science Foundation of China(No.52300170).
文摘Catalytic CO_(2)-to-methanol conversion presents a synergistic approach for concurrent greenhouse gas abatement and sustainable energy carrier synthesis.Single-atom catalysts(SACs)with maximized atomic utilization,tailored electronic configurations and unique metal-support interactions,exhibit superior performance in CO_(2) activation and methanol synthesis.This review systematically compares reaction mechanisms and pathways across thermal,photocatalytic and electrocatalytic systems,emphasizing structure-activity relationships governed by active sites,coordination microenvironments and support functionalities.Through case studies of representative SACs,we elucidate how metal-support synergies dictate intermediate binding energetics and methanol selectivity.A critical analysis of reaction parameters(e.g.,temperature,pressure)reveals condition-dependent catalytic behaviors in thermal system,with fewer studies in photo/electrocatalytic systems identified as key knowledge gaps.While thermal catalysis achieves industrially viable methanol yields,the scalability is constrained by energy-intensive operation and catalyst sintering.Conversely,photo/electrocatalytic routes offer renewable energy integration but suffer from inefficient charge dynamics and mass transport limitations.To address the challenges,we propose strategic research priorities on precise design of active sites,synergy of multiple technological pathways,development of intelligent catalytic systems and diverse CO_(2) feedstock compatibility.These insights establish a framework for developing next-generation SACs,offering both theoretical foundations and technological blueprints for developing carbon-negative catalytic technologies.
基金supported by the National Natural Science Foundation of China(Nos.22422806,22378136,and 22138003)the Guangdong Pearl River Talents Program(Nos.2021QN02C847and 2021ZT09Z109)+4 种基金the Natural Science Foundation of Guangdong Province(Nos.2024A1515011196 and 2023B1515040005)the Fundamental Research Funds for the Central Universities(Nos.2024ZYGXZR011,2025ZYGXZR025)the Science and Technology Program of Guangzhou(No.2025A04J5244)the State Key Laboratory of Pulp and Paper Engineering(No.2024ZD09)the TCL Young Talent Program。
文摘The breaking of the symmetric electronic distribution of single-atom catalysts is effective in improving the intrinsic activity.However,traditional modification strategies can only disrupt the electronic distribution in one dimension,resulting in limited regulation of electronic structure.Herein,we report a multidimensional coordination strategy to significantly break the symmetrical electron distribution of the metal single site to achieve highly efficient electrochemical CO_(2) reduction reaction(CO_(2) RR).Ni singleatom sites decorated with planar P and axial Cl atoms are successfully constructed on carbon support(Ni-NPCl-C).Ni-NPCl-C affords CO Faraday efficiency over 90%in a wide potential window range from-0.5 to-1.2 V and an ultrahigh turnover frequency of 1.17×10^(5)h^(-1),much superior to its counterparts with single-dimensional coordination.Ni-NPCl-C can be further applied as a bifunctional catalyst to construct a rechargeable Zn-CO_(2) battery.Spectroscopic characterizations and theoretical calculations demonstrate that the dual adjustments with axial Cl and planar P can synergistically disrupt the electron distribution in two dimensions to increase electrons around Ni sites with the upshift of the d-band center,thereby facilitating the formation of*COOH intermediates and improving the CO_(2) RR performance.
基金supports from the National Natural Science Foundation of China(Grant Nos.12305372 and 22376217)the National Key Research&Development Program of China(Grant Nos.2022YFA1603802 and 2022YFB3504100)+1 种基金the projects of the key laboratory of advanced energy materials chemistry,ministry of education(Nankai University)key laboratory of Jiangxi Province for persistent pollutants prevention control and resource reuse(2023SSY02061)are gratefully acknowledged.
文摘Using photoelectrocatalytic CO_(2) reduction reaction(CO_(2)RR)to produce valuable fuels is a fascinating way to alleviate environmental issues and energy crises.Bismuth-based(Bi-based)catalysts have attracted widespread attention for CO_(2)RR due to their high catalytic activity,selectivity,excellent stability,and low cost.However,they still need to be further improved to meet the needs of industrial applications.This review article comprehensively summarizes the recent advances in regulation strategies of Bi-based catalysts and can be divided into six categories:(1)defect engineering,(2)atomic doping engineering,(3)organic framework engineering,(4)inorganic heterojunction engineering,(5)crystal face engineering,and(6)alloying and polarization engineering.Meanwhile,the corresponding catalytic mechanisms of each regulation strategy will also be discussed in detail,aiming to enable researchers to understand the structure-property relationship of the improved Bibased catalysts fundamentally.Finally,the challenges and future opportunities of the Bi-based catalysts in the photoelectrocatalytic CO_(2)RR application field will also be featured from the perspectives of the(1)combination or synergy of multiple regulatory strategies,(2)revealing formation mechanism and realizing controllable synthesis,and(3)in situ multiscale investigation of activation pathways and uncovering the catalytic mechanisms.On the one hand,through the comparative analysis and mechanism explanation of the six major regulatory strategies,a multidimensional knowledge framework of the structure-activity relationship of Bi-based catalysts can be constructed for researchers,which not only deepens the atomic-level understanding of catalytic active sites,charge transport paths,and the adsorption behavior of intermediate products,but also provides theoretical guiding principles for the controllable design of new catalysts;on the other hand,the promising collaborative regulation strategies,controllable synthetic paths,and the in situ multiscale characterization techniques presented in this work provides a paradigm reference for shortening the research and development cycle of high-performance catalysts,conducive to facilitating the transition of photoelectrocatalytic CO_(2)RR technology from the laboratory routes to industrial application.
基金funded by the“Pioneer”and“Leading Goose”R&D Program of Zhejiang(No.2023C03017)China Postdoctoral Science Foundation(No.GZC20230373)+5 种基金Zhejiang Provincial Natural Science Foundation of China(No.LQ24B070010)CMA Key Open Laboratory of Transforming Climate Resources to Economy(No.2024004K)Natural Science Foundation of Huzhou City(No.2024YZ19)the National Natural Science Foundation of China(Nos.22202032,22406020 and 22406019)the Key Research and Development Projects of Xinjiang Uygur Autonomous Region,China(No.2022B02031)Joint Fund of the Zhejiang Provincial Natural Science Foundation of China(No.LBMHY25E060009)。
文摘Elucidating the active site formation mechanism of bismuth(Bi)-based catalysts in electrochemical CO_(2)reduction remains challenging for achieving high activity,selectivity,and long-term stability.Here we confirm through experimental results that Bi-based catalysts containing halogen ions(I^(-),Cl^(-),Br^(-))and SO_(4)^(2-)maintain the system stability,keeping Faraday efficiency of formic acid above90%in the current range of 50-800 mA cm^(-2).In contrast,anions containing S^(2-)and NO_(3)^(-)in the electrolyte can be reduced to produce by-products.These anions and their by-products could poison the active center,leading to increased side reactions and thus significantly reducing the Faraday efficiency of formic acid.The combination of non-in situ and in situ characterization results revealed that the Bi-based catalysts all underwent the transition from the initial state to the Bi/Bi_(2)O_(2)CO_(3)(BOC)intermediate state in high-concentration KHCO_(3) solution,and the different anions could selectively modulate the degree of exposure of specific crystalline surfaces of BOC.At the late stage of the reaction,BOC was completely converted to metal Bi and became the real active center.Combined with in situ IR and DFT calculations,it is further verified that^(*)OCHO is the key intermediate on the metallic Bi surface,which is most favorable for formic acid formation.This study reveals the key mechanism by which anions affect the formation of active sites via modulating the catalyst reconstruction process,which provides an important theoretical basis for the design and optimization of test conditions of Bi-based catalysts.
基金financially supported by the National Natural Science Foundation of China(No.52172264)the National Key Research and Development Program of China(No.2022YFC3900802)。
文摘To promote CO_(2)redox kinetics on the cathode of hybrid sodium-carbon dioxide(Na-CO_(2))batteries,hollow cubic CuS nanoboxes were encapsulated in polypyrrole and polydopamine by in situ polymerization of pyrrole and dopamine monomers,respectively,and coupled with high-temperature heat treatment to obtain nitrogen-carbon encapsulated Cu_(x)S@NC_(PPy)and Cu_(x)S@NCPDA catalysts.The results show that the encapsulation of nitrogen-doped carbon not only increases the specific surface area and improves the electron affinity but also promotes the synergistic interaction between the CuS-based active species and the defect carbon,thus providing abundant active sites for CO_(2)conversion.The electrochemical performances of the carbon-coated modified samples were all improved,especially the hybrid Na-CO_(2)battery based on Cu_(x)S@NC_(PPy),which showed a low voltage gap of 0.74 V at 0.1 mA/cm^(2)and a high power density of 3.42 mW/cm^(2).
基金financially supported by the National Natural Science Foundation of China(52271200)Guangdong Basic and Applied Basic Research Foundation(2024A1515010393)USTB MatCom of Beijing Advanced Innovation Center for Materials Genome Engineering。
文摘Electrocatalytic carbon dioxide reduction is a crucial method for addressing energy issues and achieving carbon neutrality.Doping of Cu catalysts represents an effective approach to regulate electrocatalytic carbon dioxide reduction.This review article summarizes the research progress on improving the performance of Cu-based material electrocatalysts through doping regulation.The background,fundamental research,evaluation parameters,and methods for catalyst design,along with their influencing factors,are introduced.Emphasis is placed on the impact of doping with different elements(such as noble metals,transition metals,main-group metals,non-metals,etc.)on the performance of Cu-based catalysts,including the mechanisms for enhancing activity,selectivity,and stability.In-situ characterization techniques have revealed the structural evolution and catalytic mechanisms during the doping process.Mechanistic studies,leveraging the ever-advancing computational capabilities and high-throughput methods,have given rise to typical computational descriptors like volcano plots,free-energy diagrams,and machine-learning-based approaches.These descriptors have become key tools for screening high-efficiency catalysts in various application scenarios of the electrochemical carbon dioxide reduction reaction(CO_(2)RR).This article comprehensively summarizes the current research achievements and looks ahead to the future,indicating that strengthening the combination of theory and experiment and exploring industrial applications are the future research directions,aiming to provide a comprehensive reference for the development of highly efficient doped Cu-based electrocatalysts.
基金supported by the National Natural Science Foundation of China(No.51878292).
文摘Large-scale CO_(2)emissions have exacerbated the greenhouse effect,reinforcing the critical need for efficient CO_(2)mitigation methods.Plasma-catalytic technology enables CO_(2)conversion under mild conditions,especially for CO_(2)methanation(the Sabatier reaction),which has attracted significant attention due to its economic benefits and the potential for safe energy transportation via existing natural gas pipelines.The development of high-performance CO_(2)methanation catalysts remains an ongoing and long-term objective,and there is a lack of adequate in-situ characterization techniques to investigate the mechanisms.This study focuses on the Ni/La_(2)O_(3)(LN)catalyst and introduces two CO_(2)activation strategies through F and Na modifications:the Ni-Ov-Ni site activation with electron transfer from Ni0 under low-power conditions and basic site activation under high-power conditions.The LN-NaF catalysts enhance CO_(2)methanation activity across the entire power range compared to LN,achieving a CO_(2)conversion of 86.3%and CH4 selectivity of 99.4%.Additionally,LN-F(h)reaches a CH4 yield 4.15 times higher than that of LN at low power.Furthermore,in-situ diffuse reflectance infrared Fourier transform(DRIFT)spectroscopy with a self-made reactor are performed under plasma-catalytic conditions to reveal the CO_(2)adsorption and conversion mechanisms,indicating that different dopants(F,Na,and NaF)exhibit promoting effects on different intermediates,resulting in variations in CO_(2)methanation activity.This study provides valuable insights for improving catalyst performance and a thorough comprehension of mechanisms in CO_(2)methanation.
基金supported by the National Natural Sci-ence Foundation of China(Nos.U21A20288 and 21978280).
文摘Developing green and efficient methods to acquire lignocellulose-based chemicals with high added value is beneficial for facilitating green chemistry and sustainable development.The goal of this study is to demonstrate that bio-based benzaldehyde,a noteworthy high-value chemical,is able to be directionally prepared from lignocellulosic biomass.This new control-lable transformation was materialized by uniting catalytic-pyrolysis of lignocellulose to toluene intermediate and catalytic oxidation of toluene intermediate to bio-based benzalde-hyde.This work also developed a highly active magnetic catalyst(CoFe_(2)O_(4)@Biochar(HTR)),achieving 77.1%benzaldehyde selectivity and 46.7%benzaldehyde yield using this catalyst.It was found that introducing the biochar carrier into the cobalt iron composite metal oxide cat-alyst enhanced hydroxyl radical formation and bio-based benzaldehyde synthesis.Based on catalyst characterizations and hydroxyl radical analysis,potential reaction mechanism for bio-based benzaldehyde synthesis was proposed.This strategy may provide a beneficial pathway for developing high-value bio-based chemical(benzaldehyde)using renewable lignocellulosic biomass.
基金supported by the National Natural Science Foundation of China(52225004 and 22276202)the National Key Research and Development Program of China(2022YFC3701804)the Youth Innovation Promotion Association of Chinese Academy of Sciences(2019045).
文摘Catalytic activity and hydrothermal stability are both crucial for the application of the selective catalytic reduction of NO_(x)with NH_(3)(NH_(3)-SCR)catalyst in diesel vehicles.In this study,a tin(Sn)-modified Ce-Nb mixed-oxide catalyst was synthesized as an NH_(3)-SCR catalyst for NO_(x)emission control.After the intro-duction of Sn,both the NH_(3)-SCR activity and the hydrothermal stability of the catalyst were remarkably promoted.Even after hydrothermal aging at 1000℃,the developed Ce_(1)Sn_(2)Nb_(1)O_(x)catalyst achieved more than 90%NO_(x)conversion at 325-500℃.Various methods,including N2-physisorption,X-ray diffraction,in-situ high-temperature X-ray diffraction,high-resolution transmission electron microscopy,X-ray pho-toelectron spectroscopy,X-ray absorption fine-structure spectroscopy,temperature-programmed reduc-tion of hydrogen,temperature-programmed desorption of ammonia,and density functional theory calculations were used to investigate the promotional effects induced by the Sn species.The characteri-zation results showed that the addition of Sn not only promoted the formation of the Ce-Nb active phase but also improved its thermal stability,contributing to the excellent NH_(3)-SCR performance and hydrothermal stability.This study provides an excellent sintering-resistance catalyst for the application of diesel engine NO_(x)emission control.
基金supported by the National Key Research and Develop-ment Pr0gram of China(Nos.2021YFA1501104 and 2023YFA1506802)the National Natural Science Foundation of China(No.22032001).
文摘Ethanol steam reforming(ESR)represents a promising route for sustainable hydrogen production,leveraging the high hydrogen content,renewability,and logistical advantages of ethanol.Although Ni-based catalysts are leading non-noble candidates for ESR,their practical deployment is hindered by compromised H_(2) production efficiency and rapid deactivation.In this work,we combined catalyst synthesis,kinetic analysis,and mechanistic investigation to elucidate the effectsof Ni particle size(3-9 nm)on ESR performance of Ni/CeO_(2) catalysts.These Ni/CeO_(2) catalysts were prepared via a citric acid-assisted coprecipitation method,and systematically characterized using complementary techniques,including high-resolution transmission electron microscopy(HRTEM),in situ X-ray photoelectron spectroscopy(XPS),hydrogen temperature-programmed reduction(H_(2)-TPR),Raman spectroscopy,O_(2)/CO chemisorption,and temperature-programmed surface reaction(TPSR)analyses.Mechanistic study revealed that ethanol dehydrogenation to acetaldehyde is the rate-determining step,defining the intrinsic activity of Ni sites,whereas C-C bond cleavage governs H_(2) selectivity in ESR.At smaller Ni sizes(e.g.,3.1 nm),larger CeO_(2) surface was exposed,which promoted acetaldehyde condensation to acetone,and consequently reduced H_(2) production efficiency.The Ni/CeO_(2) catalyst with~5 nm of Ni particles afforded the highest H_(2) yield(66.3%)and outstanding stability by balancing dehydrogenation activity,H_(2) selectivity,and coking resistance.Conversely,larger Ni particles(>6 nm)facilitated methanation reaction and catalyst deactivation.This work reconciles prior inconsistencies in the Ni size effects on ESR and provides guidance for the design of efficient and durable Ni-based catalysts for H_(2) production.
基金supported by the National Natural Science Foundation of China(Nos.22025604 and 22276204)the National Key R&D Program of China(Nos.2023YFC3708401 and 2022YFC3800404).
文摘To develop efficient catalysts for ambient carbon monoxide(CO)oxidation is significant for indoor air purification and also for many industrial applications.In this work,the catalytic activity for CO oxidation were enhanced by tuning the metal-support interaction of Ru/CeO_(2)catalysts.A series of Ru/CeO_(2)catalysts were synthesized by an impregnation method with calcination at 100,200,400 and 600℃,respectively,to regulate the Ru-CeO_(2)interaction.We discovered that low temperature calcination(100℃)induced more Ru-O-Ce bonds and stronger Ru-CeO_(2)interaction,while high temperature calcination(≥400℃)caused the agglomeration of Ru species with more Ru-O-Ru bonds and weaker Ru-CeO_(2)interaction,resulting in the lower redox capacity of these catalysts,as well as lower catalytic activity for CO oxidation.Only calcination at moderate 200℃ can induce the moderate interaction between Ru species and CeO_(2)support,which can keep the high dispersion of RuO_(x)species with the high redox capacity,thus leading to complete elimination of 500 ppm CO at room temperature on Ru/Ce-200 catalyst.
基金Project supported by the National Natural Science Foundation of China(22221001,22131007,22102193)the National Key R&D Program of China(2021YFA1501101,2022YFA1504601)+1 种基金the 111 Project(B20027)a Startup Program of the State Key Laboratory for Oxo Synthesis and Selective Oxidation of LICP(EOSX0184)。
文摘Heterogeneous precious metal catalysts are prone to agglomeration during preparation,requiring high usage with consequently high costs.Maximizing the efficiency of precious-metal utilization is of great significance in the design of supported precious metal catalysts.Herein,2,2'-bipyridyl-5,5'-dicarboxylic acid was used as the ligand in constructing the UiO-67-Ce-BPyDC framework with Ce^(4+)coordination.This framework enables precise adsorption and coordination of Pd2+at the nitrogen sites of pyridine,promoting high dispersion of the Pd species at a single site,thereby facilitating controlled palladium loading.This precursor was used to fabricate supported Pd-based catalysts on CeO_(2)(Pd-N/CeO_(2)-P)via pyrolysis.Notably,because the Pd species are homogeneously distributed on CeO_(2)with strong interactions,Pd-N/CeO_(2)-P exhibits remarkable efficiency in cleaving the C-O bonds of diphenyl ether(DPE)to produce cyclohexanol,with a selectivity of 72.1%.The origin of the high selectivity of cyclohexanol is further elucidated using theoretical calculations;that is,DPE undergoes not only hydrogenolysis on Pd-N/CeO_(2)-P,but also hydrolysis to produce more cyclohexanol.This study not only demonstrates a successful strategy for designing highly dispersed metal catalysts,but also underscores the importance of such tailored catalysts in the advancement of sustainable lignin depolymerization technologies.
基金supported by National Natural Science Foundation of China(21776047,21203028)
文摘The Co/CeO2 catalysts promoted with Ba or K were prepared to study the effect of promoter on the catalytic performance of ammonia synthesis. The results show that the presence of Ba or K promoter changes the properties of CeO2-supported Co catalysts including the surface area, the crystallite size and the morphology of CeO2, the reduction degree of cobalt species and the adsorption performance of hydrogen and nitrogen. As a consequence, the samples promoted with an appropriate amount of Ba show higher ammonia synthesis rates, while the catalysts with high Ba loading or K promoter all exhibit low catalytic activities.
基金supported by the National Natural Science Foundation of China (21307038 and 21577046)Key Project of Chinese Ministry of Education (212115)Physical Chemistry Experiment of Huanggang Normal University (2015CK12)~~
文摘Pt/Ni catalysts modified with CeO2 nanoparticles were prepared by simple composite electrodeposition of Ni and CeO2,and spontaneous Ni partial replacement by Pt processes.The as-prepared CeO2-modified Pt/Ni catalysts showed enhanced catalytic performance for ethanol electro-oxidation compared with pure Pt/Ni,and acetate species were proposed to be the main products of the oxidation when using these catalysts.The content of CeO2 in the as-prepared catalysts influenced their catalytic activity,with Pt/NiCe2（obtained from an electrolyte containing 100 mg/L CeO2 nanoparticles） exhibiting higher activity and relatively better stability in ethanol electro-oxidation.This was mainly due to the oxygen storage capacity of CeO2,the interaction between Pt and CeO2/Ni,and the relatively small contact and charge transfer resistances.The results of this work thus suggest that electrocatalysts with low price and high activity can be rationally designed and produced by a simple route for use in direct ethanol fuel cells.
基金supported by the National Natural Science Foundation of China (11475041, 11175036, 21373037)the Fundamental Research Funds for the Central Universities (DUT16QY49)~~
文摘CO2 selective reduction to CO with H2 over a CeO2-supported nano-Au catalyst at atmospheric pres- sure was investigated. A high CO2 conversion, approaching the thermodynamic equilibrium value, and nearly 100% CO selectivity were obtained. The surface formate intermediates generated during the reverse water-gas shift reaction at 400 ℃ were identified using in situ diffuse-reflectance infra- red Fourier-transform spectroscopy. The formate consumption to give CO and H20, determined using mass spectrometry, indicated that the reaction proceeded via an associative formate mecha- nism; this contributes to the high Au/CeO2 catalytic activity at low temperatures.
