Reverse water gas shift（RWGS） reaction can be served as a pivotal stage of transitioning the abundant CO;resource into chemicals or hydrocarbon fuels, which is attractive for the CO;utilization and of eventually sig...Reverse water gas shift（RWGS） reaction can be served as a pivotal stage of transitioning the abundant CO;resource into chemicals or hydrocarbon fuels, which is attractive for the CO;utilization and of eventually significance in enabling a rebuilt ecological system for unconventional fuels. This concept is appealing when the process is considered as a solution for the storage of renewable energy, which may also find a variety of potential end uses for the outer space exploration. However, a big challenge to this issue is the rational design of high temperature endurable RWGS catalysts with desirable CO product selectivity. In this work, we present a comprehensive overview of recent publications on this research topic,mainly focusing on the catalytic performance of RWGS reaction over three major kinds of heterogeneous catalysts, including supported metal catalysts, mixed oxide catalysts and transition metal carbides. The reaction thermodynamic analysis, kinetics and mechanisms are also described in detail. The present review attempts to provide a general guideline about the construction of well-performed heterogeneous catalysts for the RWGS reaction, as well as discussing the challenges and further prospects of this process.展开更多
A full-wave analysis of the electromagnetic problem of a three-dimensional(3-D)antenna radiating through a 3-D dielectric radome is preserued.The problem is formulated using the Poggio-Miller-Chang-Harrington-Wu(PMCHW...A full-wave analysis of the electromagnetic problem of a three-dimensional(3-D)antenna radiating through a 3-D dielectric radome is preserued.The problem is formulated using the Poggio-Miller-Chang-Harrington-Wu(PMCHW)approach for homogeneous dielectric objects and the electric field integral equation for conducting objects.The integral equations are discretized by the method of moment(MoM),in which the conducting and dielectric surface/interfaces are represented by curvilinear triangular patches and the unknown equivalent electric and magnetic currents are expanded using curvilinear RWG basis functions.The resultant matrix equation is then solved by the multilevel fast multipole algorithm(MLFMA)and fast far-field approximation(FAFFA)is used to further accelerate the computation.The radiation patterns of dipole arrays in the presence of radomes are presented.The numerical results demonstrate the accuracy and versatility of this method.展开更多
Fe-based catalysts are efficient systems for CO_(2)conversion via reverse water-gas shift(rWGS)reaction.Nevertheless,the nature of the active phase,namely metallic iron,iron oxide or iron carbide remains a subject of ...Fe-based catalysts are efficient systems for CO_(2)conversion via reverse water-gas shift(rWGS)reaction.Nevertheless,the nature of the active phase,namely metallic iron,iron oxide or iron carbide remains a subject of debate which our paper is meant to close.Fe0 is a much better catalyst for the rWGS than Fe_(3)C.The activity of Fe0 can be promoted by the addition of Cs and Cu whose presence hinders iron carburisation while favouring both higher conversion and enhanced selectivity.When the samples are aged in the rWGS reaction mixture during stability test a new phase appear:Fe_(5)C_(2),resulting in a more active but less selective catalysts than Fe0 for the rWGS reaction.Hence our results indicate that we could potentially achieve an optimal activity/selective balance upon finely tuning the proportion Fe/Fe_(5)C_(2).Beyond the fundamental information concerning active phase we have observed the presence of advanced Fischer-Tropsch-like products at ambient pressure opening new opportunities for the design of hybrid rWGS/Fischer-Tropsch systems.展开更多
Converting CO_(2)to CO through the thermocatalytic reverse water gas shift(RWGS)is an industrially relevant reaction for carbon circularity.Improvements in catalyst design for this reaction are highly required,not onl...Converting CO_(2)to CO through the thermocatalytic reverse water gas shift(RWGS)is an industrially relevant reaction for carbon circularity.Improvements in catalyst design for this reaction are highly required,not only in terms of active metal sites but also as novel possibilities for oxide support involvement in the reactant activation and surface transportation of the intermediate species.Here,we present the concept of engineering dual-active sites on CeO_(x)-modified defective MgO to enhance CO_(2)adsorption and H species spillover.Compared to bulk oxide-supported catalysts,the Pt/Ce_(4.1)-MgO catalyst with abundant MgO-defects enhanced by cerium-modification exhibits a significantly high CO_(2)conversion(56.1%,near to equilibrium conversion)and a CO formation rate of up to 491μmol g_(cat.)^(-1)h^(-1)with a selectivity to carbon monoxide exceeding 97%at 600℃.This high-performance dual-site catalyst was studied in detail using many techniques,including H_(2)/D_(2)kinetic isotope effects,temperature programmed and kinetic experiments,and CO_(2)adsorption isotherms.The data prove that the highly dispersed Ce,in the form of single atoms or small surface nano patches,enhances the formation of coordinatively unsaturated sites,which favour CO_(2)absorption and reduction in the presence of H spillover migrating from Pt nanoparticles.This novel design leads to improved CO_(2)reduction to CO.In-situ diffuse reflectance infrared Fourier transform spectroscopy(DRIFTS)experiments show that the enhanced carbonate and formate species contributed to the improved RWGS performance over the Pt/Ce_(4.1)-MgO catalyst.These results pave the way for designing efficient CO_(2)hydrogenation catalysts by the creation of the unsaturated oxide-oxide interface on the support.展开更多
基金supported by the National Natural Science Foundation of China(Nos.21506204 and 21476226)China Ministry of Science and Technology under contact of 2016YFB0600902+3 种基金the Strategic Priority Research Program of the Chinese Academy of Sciences(XDB17020400)State Grid Cooperation of China(SGRI-DL-71-16-015)Dalian Science Foundation for Distinguished Young Scholars(2016RJ04)the Youth Innovation Promotion Association of CAS
文摘Reverse water gas shift（RWGS） reaction can be served as a pivotal stage of transitioning the abundant CO;resource into chemicals or hydrocarbon fuels, which is attractive for the CO;utilization and of eventually significance in enabling a rebuilt ecological system for unconventional fuels. This concept is appealing when the process is considered as a solution for the storage of renewable energy, which may also find a variety of potential end uses for the outer space exploration. However, a big challenge to this issue is the rational design of high temperature endurable RWGS catalysts with desirable CO product selectivity. In this work, we present a comprehensive overview of recent publications on this research topic,mainly focusing on the catalytic performance of RWGS reaction over three major kinds of heterogeneous catalysts, including supported metal catalysts, mixed oxide catalysts and transition metal carbides. The reaction thermodynamic analysis, kinetics and mechanisms are also described in detail. The present review attempts to provide a general guideline about the construction of well-performed heterogeneous catalysts for the RWGS reaction, as well as discussing the challenges and further prospects of this process.
基金the National Natural Science Foundation of China(60431010)
文摘A full-wave analysis of the electromagnetic problem of a three-dimensional(3-D)antenna radiating through a 3-D dielectric radome is preserued.The problem is formulated using the Poggio-Miller-Chang-Harrington-Wu(PMCHW)approach for homogeneous dielectric objects and the electric field integral equation for conducting objects.The integral equations are discretized by the method of moment(MoM),in which the conducting and dielectric surface/interfaces are represented by curvilinear triangular patches and the unknown equivalent electric and magnetic currents are expanded using curvilinear RWG basis functions.The resultant matrix equation is then solved by the multilevel fast multipole algorithm(MLFMA)and fast far-field approximation(FAFFA)is used to further accelerate the computation.The radiation patterns of dipole arrays in the presence of radomes are presented.The numerical results demonstrate the accuracy and versatility of this method.
基金provided by the Royal Society Research Grant RSGR1180353partially sponsored by the CO2Chem UK through the Engineering and Physical Sciences Research Council(EPSRC)grant EP/P026435/1the Spanish Ministry of Science and Innovation through the projects RYC2018-024387-I and PID2019-108502RJ-I00.
文摘Fe-based catalysts are efficient systems for CO_(2)conversion via reverse water-gas shift(rWGS)reaction.Nevertheless,the nature of the active phase,namely metallic iron,iron oxide or iron carbide remains a subject of debate which our paper is meant to close.Fe0 is a much better catalyst for the rWGS than Fe_(3)C.The activity of Fe0 can be promoted by the addition of Cs and Cu whose presence hinders iron carburisation while favouring both higher conversion and enhanced selectivity.When the samples are aged in the rWGS reaction mixture during stability test a new phase appear:Fe_(5)C_(2),resulting in a more active but less selective catalysts than Fe0 for the rWGS reaction.Hence our results indicate that we could potentially achieve an optimal activity/selective balance upon finely tuning the proportion Fe/Fe_(5)C_(2).Beyond the fundamental information concerning active phase we have observed the presence of advanced Fischer-Tropsch-like products at ambient pressure opening new opportunities for the design of hybrid rWGS/Fischer-Tropsch systems.
基金financially supported by the National Key Research and Development Program of China(2024YFB4006600)the NSFC of China(22472168 and 22172161)+4 种基金the Natural Science Foundation of Liaoning Province(2024-MSBA-57)the Dalian Institute of Chemical Physics(DICP I202421)the Energy Revolution S&T Program of Yulin Innovation Institute of Clean Energy(E411030705)the support from the CAS President’s International Fellowship Initiative(PIFI)programthe SCOPE ERC Synergy project(ID 810182)。
文摘Converting CO_(2)to CO through the thermocatalytic reverse water gas shift(RWGS)is an industrially relevant reaction for carbon circularity.Improvements in catalyst design for this reaction are highly required,not only in terms of active metal sites but also as novel possibilities for oxide support involvement in the reactant activation and surface transportation of the intermediate species.Here,we present the concept of engineering dual-active sites on CeO_(x)-modified defective MgO to enhance CO_(2)adsorption and H species spillover.Compared to bulk oxide-supported catalysts,the Pt/Ce_(4.1)-MgO catalyst with abundant MgO-defects enhanced by cerium-modification exhibits a significantly high CO_(2)conversion(56.1%,near to equilibrium conversion)and a CO formation rate of up to 491μmol g_(cat.)^(-1)h^(-1)with a selectivity to carbon monoxide exceeding 97%at 600℃.This high-performance dual-site catalyst was studied in detail using many techniques,including H_(2)/D_(2)kinetic isotope effects,temperature programmed and kinetic experiments,and CO_(2)adsorption isotherms.The data prove that the highly dispersed Ce,in the form of single atoms or small surface nano patches,enhances the formation of coordinatively unsaturated sites,which favour CO_(2)absorption and reduction in the presence of H spillover migrating from Pt nanoparticles.This novel design leads to improved CO_(2)reduction to CO.In-situ diffuse reflectance infrared Fourier transform spectroscopy(DRIFTS)experiments show that the enhanced carbonate and formate species contributed to the improved RWGS performance over the Pt/Ce_(4.1)-MgO catalyst.These results pave the way for designing efficient CO_(2)hydrogenation catalysts by the creation of the unsaturated oxide-oxide interface on the support.
