Converting CO_(2) into value-added chemicals and fuels through various catalytic methods to lower the atmospheric CO_(2) concentration has been developed to be a crucial means to alleviate the energy shortage and amel...Converting CO_(2) into value-added chemicals and fuels through various catalytic methods to lower the atmospheric CO_(2) concentration has been developed to be a crucial means to alleviate the energy shortage and ameliorate the ever-fragile environment status. However, the complexity of the CO_(2) conversion reaction and the strong reduction conditions lead to the inevitable structural evolution, making it difficult for the prior design of suitable catalytic materials. Herein, to guide the rational design of efficient catalysts,we will be centered on the thermal, electro, and photo-induced structural evolution and active species identification during the CO_(2) conversion, including the in situ/operando characterization techniques monitoring the activation, steady, and deactivation stage of the catalysts as well as the inherent restructuring mechanism towards active species. Besides, the future challenges and opportunities on the merits of combining the structural evolution with the adsorbed intermediates recognized by ultra-fast spectroscopic techniques, simultaneously, the combination of theoretical simulation and the results of in situ experiments will also be addressed. This review can not only guide the identification of real active species, but also provide an approach to design the specific active species towards CO_(2) conversion, rather than only focusing on activity, for the purpose of practical industrial application.展开更多
Electrocatalytic semi-hydrogenation of acetylene(C_(2)H_(2))over copper nanoparticles(Cu NPs)offers a promising non-petroleum alternative for the green production of ethylene(C2H4).However,server hydrogen evolution re...Electrocatalytic semi-hydrogenation of acetylene(C_(2)H_(2))over copper nanoparticles(Cu NPs)offers a promising non-petroleum alternative for the green production of ethylene(C2H4).However,server hydrogen evolution reaction(HER)competition in this process prominently decreases C2H4 selectivity,thereby hindering its practical application.Herein,a Cu-based composite catalyst,wherein porous carbon with nanoscale pores was used as a support,is constructed to gather the C_(2)H_(2) feedstocks for suppressing the undesirable HER.As a result,the as-prepared catalyst exhibited C_(2)H_(2) conversion of 27.1%and C_(2)H_(4) selectivity of 88.4%at a C2H4 partial current density of 0.25 A/cm^(2) under optimal−1.0 V versus reversible hydrogen electrode(RHE)under the simulated coal-derived C_(2)H_(2) atmosphere,significantly outperforming the single Cu NPs counterparts.In addition,a series of in situ and ex situ experimental results show that not only the porous nature of the carbon support but also the stabilized Cu^(0)–Cu^(+) dual active sites through the strong metal–support interactions enhance the adsorption capacity of C_(2)H_(2),leading to high C_(2)H_(2) partial pressure,restraining the HER and thus improving the C2H4 selectivity.展开更多
Electrocatalytic nitric oxide(NO)reduction is a promising strategy to produce ammonia.Developing a facile approach to synthesize efficient catalysts with enhanced NO electroreduction performance is highly desirable.He...Electrocatalytic nitric oxide(NO)reduction is a promising strategy to produce ammonia.Developing a facile approach to synthesize efficient catalysts with enhanced NO electroreduction performance is highly desirable.Here,a series of Ru-doped Cu materials are constructed through in situ electroreduction of corresponding metal hydroxides.The optimized Ru_(0.05)Cu_(0.95)exhibits superior electrocatalytic performance for ammonia synthesis by using NO/Ar(1/4,n/n)as the feedstocks(Faradaic efficiency:64.9%,yield rate:17.68μmol cm^(-2)h^(-1)),obviously outperforming Cu counterpart(Faradaic efficiency:33.0%,yield rate:5.73μmol cm^(-2)h^(-1)).Electrochemical in situ Fourier transform infrared(FTIR)spectroscopy and online differential electrochemical mass spectrometry(DEMS)are adopted to detect intermediates and unveil the possible reaction pathway.The downshift of the Cu d-band center induced by Ru doping facilitates the rate-limiting hydrogenation step and decreases the desorption energy of NH_(3),leading to high Faradaic efficiency and yield of ammonia.展开更多
Understanding and manipulating synthetic progress for precisely controlling the components and defects of nanomaterials is an important and challenging task in materials synthesis and nanocatalysis.Metal phosphides(MP...Understanding and manipulating synthetic progress for precisely controlling the components and defects of nanomaterials is an important and challenging task in materials synthesis and nanocatalysis.Metal phosphides(MPs)have been explored as cheap advanced materials in various catalytic fields.MP materials are usually synthesized through gas-solid phosphorization reaction in a trial-to-error manner,but their formation mechanism and the origin of controlled synthesis remain unclear.Here,we combine in situ thermogravimetrc analysis-mass spectrometry(TG-MS)and quasi-in situ X-ray powder diffraction(XRD)analysis to probe the transformation mechanism from metal oxides(MOs)to MPs during the phosphorization process mediated by hypophosphite.Temperature,time,and the amount of hypophosphite are revealed as the driven forces while oxophilicity and crystallinity as the impeded forces,simultaneously control the component and defect level of a series of MP(M=Ni,Co,W,Mo,and Nb).The as-obtained WO2.9/WP is proved to be an efficient Z-scheme photocatalyst for oxidative coupling of methane with the total C2+production and C2H4 selectivity in C2+products reaching 10.75 pmolg-1 and 98.25%.Our work provides a fundamental understanding of the phosphorization treatment and thereby guides a viable synthetic route to the controlled synthesis of MOx-δ,MP,MOx-δ/MP,and MP/M heterostructured materials.展开更多
基金the National Natural Science Foundation of China(No.22209120)the China Postdoctoral Science Foundation (No.2022M722364) for financial support。
文摘Converting CO_(2) into value-added chemicals and fuels through various catalytic methods to lower the atmospheric CO_(2) concentration has been developed to be a crucial means to alleviate the energy shortage and ameliorate the ever-fragile environment status. However, the complexity of the CO_(2) conversion reaction and the strong reduction conditions lead to the inevitable structural evolution, making it difficult for the prior design of suitable catalytic materials. Herein, to guide the rational design of efficient catalysts,we will be centered on the thermal, electro, and photo-induced structural evolution and active species identification during the CO_(2) conversion, including the in situ/operando characterization techniques monitoring the activation, steady, and deactivation stage of the catalysts as well as the inherent restructuring mechanism towards active species. Besides, the future challenges and opportunities on the merits of combining the structural evolution with the adsorbed intermediates recognized by ultra-fast spectroscopic techniques, simultaneously, the combination of theoretical simulation and the results of in situ experiments will also be addressed. This review can not only guide the identification of real active species, but also provide an approach to design the specific active species towards CO_(2) conversion, rather than only focusing on activity, for the purpose of practical industrial application.
基金We acknowledge the National Natural Science Foundation of China(Nos.22271213 and 22209120).
文摘Electrocatalytic semi-hydrogenation of acetylene(C_(2)H_(2))over copper nanoparticles(Cu NPs)offers a promising non-petroleum alternative for the green production of ethylene(C2H4).However,server hydrogen evolution reaction(HER)competition in this process prominently decreases C2H4 selectivity,thereby hindering its practical application.Herein,a Cu-based composite catalyst,wherein porous carbon with nanoscale pores was used as a support,is constructed to gather the C_(2)H_(2) feedstocks for suppressing the undesirable HER.As a result,the as-prepared catalyst exhibited C_(2)H_(2) conversion of 27.1%and C_(2)H_(4) selectivity of 88.4%at a C2H4 partial current density of 0.25 A/cm^(2) under optimal−1.0 V versus reversible hydrogen electrode(RHE)under the simulated coal-derived C_(2)H_(2) atmosphere,significantly outperforming the single Cu NPs counterparts.In addition,a series of in situ and ex situ experimental results show that not only the porous nature of the carbon support but also the stabilized Cu^(0)–Cu^(+) dual active sites through the strong metal–support interactions enhance the adsorption capacity of C_(2)H_(2),leading to high C_(2)H_(2) partial pressure,restraining the HER and thus improving the C2H4 selectivity.
基金financially supported by the National Natural Science Foundation of China(22071173)the Natural Science Foundation of Tianjin City(20JCJQJC00050,17JCJQJC44700)。
文摘Electrocatalytic nitric oxide(NO)reduction is a promising strategy to produce ammonia.Developing a facile approach to synthesize efficient catalysts with enhanced NO electroreduction performance is highly desirable.Here,a series of Ru-doped Cu materials are constructed through in situ electroreduction of corresponding metal hydroxides.The optimized Ru_(0.05)Cu_(0.95)exhibits superior electrocatalytic performance for ammonia synthesis by using NO/Ar(1/4,n/n)as the feedstocks(Faradaic efficiency:64.9%,yield rate:17.68μmol cm^(-2)h^(-1)),obviously outperforming Cu counterpart(Faradaic efficiency:33.0%,yield rate:5.73μmol cm^(-2)h^(-1)).Electrochemical in situ Fourier transform infrared(FTIR)spectroscopy and online differential electrochemical mass spectrometry(DEMS)are adopted to detect intermediates and unveil the possible reaction pathway.The downshift of the Cu d-band center induced by Ru doping facilitates the rate-limiting hydrogenation step and decreases the desorption energy of NH_(3),leading to high Faradaic efficiency and yield of ammonia.
基金supported by the National Natural Science Foundation of China(22071173 and 22003047)the Natural Science Foundation of Tianjin City(20JCJQJC00050)the Haihe Laboratory of Sustainable Chemical Transformations(22ZYJDSS00060)。
基金the National Natural Science Foundation of China(Nos.21422104 and 21373149)for financial support.
文摘Understanding and manipulating synthetic progress for precisely controlling the components and defects of nanomaterials is an important and challenging task in materials synthesis and nanocatalysis.Metal phosphides(MPs)have been explored as cheap advanced materials in various catalytic fields.MP materials are usually synthesized through gas-solid phosphorization reaction in a trial-to-error manner,but their formation mechanism and the origin of controlled synthesis remain unclear.Here,we combine in situ thermogravimetrc analysis-mass spectrometry(TG-MS)and quasi-in situ X-ray powder diffraction(XRD)analysis to probe the transformation mechanism from metal oxides(MOs)to MPs during the phosphorization process mediated by hypophosphite.Temperature,time,and the amount of hypophosphite are revealed as the driven forces while oxophilicity and crystallinity as the impeded forces,simultaneously control the component and defect level of a series of MP(M=Ni,Co,W,Mo,and Nb).The as-obtained WO2.9/WP is proved to be an efficient Z-scheme photocatalyst for oxidative coupling of methane with the total C2+production and C2H4 selectivity in C2+products reaching 10.75 pmolg-1 and 98.25%.Our work provides a fundamental understanding of the phosphorization treatment and thereby guides a viable synthetic route to the controlled synthesis of MOx-δ,MP,MOx-δ/MP,and MP/M heterostructured materials.
