Electrochemical CO_(2)reduction into energy-carrying compounds,such as formate,is of great importance for carbon neutrality,which however suffers from high electrical energy input and liquid products crossover.Herein,...Electrochemical CO_(2)reduction into energy-carrying compounds,such as formate,is of great importance for carbon neutrality,which however suffers from high electrical energy input and liquid products crossover.Herein,we fabricated self-supported ultrathin NiCo layered double hydroxides(LDHs)electrodes as anode for methanol electrooxidation to achieve a high formate production rate(5.89 mmol h^(-1)cm^(-2))coupled with CO_(2)electro-reduction at the cathode.A total formate faradic efficiency of both anode for methanol oxidation and cathode for CO_(2)reduction can reach up to 188%driven by a low cell potential of only 2.06 V at 100 mA cm^(-2)in membrane-electrode assembly(MEA).Physical characterizations demonstrated that Ni^(3+)species,formed on the electrochemical oxidation of Ni-containing hydroxide,acted as catalytically active species for the oxidation of methanol to formate.Furthermore,DFT calculations revealed that ultrathin LDHs were beneficial for the formation of Ni^(3+)in hydroxides and introducing oxygen vacancy in NiCo-LDH could decrease the energy barrier of the rate-determining step for methanol oxidation.This work presents a promising approach for fabricating advanced electrodes towards electrocatalytic reactions.展开更多
The scaled-up synthesis of organic-free monolayer nanomaterials is highly desirable,especially in obtaining green energy by electrocatalysis.In this study,a method for the scaled-up synthesis of the series of monolaye...The scaled-up synthesis of organic-free monolayer nanomaterials is highly desirable,especially in obtaining green energy by electrocatalysis.In this study,a method for the scaled-up synthesis of the series of monolayer layered double hydroxides(LDHs)without the addition of organic solvents is reported via the separate nucleation and aging steps process.The resulting monolayer LDHs with the thicknesses of less than 1 nm showed a narrow thickness distribution.X-ray absorption fine-structure revealed that monolayer NiFe-LDH nanosheets have a number of oxygen and metal vacancies defects.As a practical application,monolayer NiFe-LDH nanosheets containing defects showed an enhanced electrocatalytic water oxidation activity compared with that of bulk NiFe-LDH.Density functional theory calculations uncovered that excellent catalytic activity is attributed to vacancies defects.The proposed method is an economical and universally applicable strategy for the scaled-up production of monolayer LDHs.展开更多
The rising CO_(2) concentration in the atmosphere due to extensive use of fossil fuels has led to serious climate and environmental issues. One efficient solution is that CO_(2) capture from industrial emissions follo...The rising CO_(2) concentration in the atmosphere due to extensive use of fossil fuels has led to serious climate and environmental issues. One efficient solution is that CO_(2) capture from industrial emissions followed its conversion into value-added chemicals driven by renewable energies. CO_(2) electroreduction(CO_(2) RR) features a green and sustainable fashion towards effective CO_(2) conversion, but still suffers from low multi-carbon selectivity and yield. Considering the pivotal role of CO intermediate in C–C coupling to multi-carbon formation, tandem CO_(2) RR systems with separated CO generation and consumption components could facilitate the coupling between *CO-based intermediates to energy-intensive multi-carbons by manipulating CO diffusion and surface coverage. In this aspect, we comprehensively reviewed the design principles of tandem systems for CO_(2) electroreduction reaction. The chemistry behind the C–C coupling regarding to their distribution and diffusion was initially introduced, which was followed by achievements on tandem architectures, from catalysts, electrodes to systems. Future directions and perspectives on advanced tandem system designs for CO_(2) RR were discussed at the end. This review contributes to the understanding of structureperformance correlations in tandem catalysis and helps guide the effective collection of multi-carbons of high-yield and highselectivity.展开更多
Copper is one of the most efficient catalysts widely investigated in electrochemical CO_(2) reduction, however, the further development of copper-based catalysts is constrained by severe stability problems. In this wo...Copper is one of the most efficient catalysts widely investigated in electrochemical CO_(2) reduction, however, the further development of copper-based catalysts is constrained by severe stability problems. In this work, we developed a method for the synthesis of highly ordered Cu Au intermetallic nanoalloys(o-CuAu) under mild conditions(< 250℃), which can convert carbon dioxide to carbon monoxide with high selectivity and can operate stably for 160 h without current decay. The improved stability is believed to be due to the increased mixing enthalpy and stronger atomic interactions between Cu and Au atoms in the intermetallic nanoalloy. In addition, XPS results, Tafel slope and in situ IR spectroscopy demonstrate that high valence gold atoms on o-CuAu surface promote the reduction of CO_(2). In contrast, the disordered CuAu nanoalloy(d-CuAu) underwent atomic rearrangement to form a Cu-rich structure on the surface, leading to reduced stability. These findings may provide insight into the rational design of stable CO_(2) RR electrocatalysts through proper structural engineering.展开更多
基金the financial support from the National Nature Science Foundation of China(22078232 and 21938008)the Haihe Laboratory of Sustainable Chemical Transformations for financial support。
文摘Electrochemical CO_(2)reduction into energy-carrying compounds,such as formate,is of great importance for carbon neutrality,which however suffers from high electrical energy input and liquid products crossover.Herein,we fabricated self-supported ultrathin NiCo layered double hydroxides(LDHs)electrodes as anode for methanol electrooxidation to achieve a high formate production rate(5.89 mmol h^(-1)cm^(-2))coupled with CO_(2)electro-reduction at the cathode.A total formate faradic efficiency of both anode for methanol oxidation and cathode for CO_(2)reduction can reach up to 188%driven by a low cell potential of only 2.06 V at 100 mA cm^(-2)in membrane-electrode assembly(MEA).Physical characterizations demonstrated that Ni^(3+)species,formed on the electrochemical oxidation of Ni-containing hydroxide,acted as catalytically active species for the oxidation of methanol to formate.Furthermore,DFT calculations revealed that ultrathin LDHs were beneficial for the formation of Ni^(3+)in hydroxides and introducing oxygen vacancy in NiCo-LDH could decrease the energy barrier of the rate-determining step for methanol oxidation.This work presents a promising approach for fabricating advanced electrodes towards electrocatalytic reactions.
基金supported by the National Nature Science Foundation of China(U1707603,21878008,21625101,U1507102,21922801)the Beijing Natural Science Foundation(2182047,2202036)the Fundamental Research Funds for the Central Universities(XK1802-6,XK1902,12060093063,2312018RC07)。
文摘The scaled-up synthesis of organic-free monolayer nanomaterials is highly desirable,especially in obtaining green energy by electrocatalysis.In this study,a method for the scaled-up synthesis of the series of monolayer layered double hydroxides(LDHs)without the addition of organic solvents is reported via the separate nucleation and aging steps process.The resulting monolayer LDHs with the thicknesses of less than 1 nm showed a narrow thickness distribution.X-ray absorption fine-structure revealed that monolayer NiFe-LDH nanosheets have a number of oxygen and metal vacancies defects.As a practical application,monolayer NiFe-LDH nanosheets containing defects showed an enhanced electrocatalytic water oxidation activity compared with that of bulk NiFe-LDH.Density functional theory calculations uncovered that excellent catalytic activity is attributed to vacancies defects.The proposed method is an economical and universally applicable strategy for the scaled-up production of monolayer LDHs.
基金supported by the National Key Research and Development Program of China (2023YFA1507901, 2022YFB4101700)the National Natural Science Foundation of China (22078232, 21938008, 22250410262)the Haihe Laboratory of Sustainable Chemical Transformations for financial support。
文摘The rising CO_(2) concentration in the atmosphere due to extensive use of fossil fuels has led to serious climate and environmental issues. One efficient solution is that CO_(2) capture from industrial emissions followed its conversion into value-added chemicals driven by renewable energies. CO_(2) electroreduction(CO_(2) RR) features a green and sustainable fashion towards effective CO_(2) conversion, but still suffers from low multi-carbon selectivity and yield. Considering the pivotal role of CO intermediate in C–C coupling to multi-carbon formation, tandem CO_(2) RR systems with separated CO generation and consumption components could facilitate the coupling between *CO-based intermediates to energy-intensive multi-carbons by manipulating CO diffusion and surface coverage. In this aspect, we comprehensively reviewed the design principles of tandem systems for CO_(2) electroreduction reaction. The chemistry behind the C–C coupling regarding to their distribution and diffusion was initially introduced, which was followed by achievements on tandem architectures, from catalysts, electrodes to systems. Future directions and perspectives on advanced tandem system designs for CO_(2) RR were discussed at the end. This review contributes to the understanding of structureperformance correlations in tandem catalysis and helps guide the effective collection of multi-carbons of high-yield and highselectivity.
基金financial support from National Nature Science Foundation of China (Nos. 22078232 and 21938008)the Science and Technology Major Project of Tianjin (Nos. 19ZXNCGX00030 and 20JCYBJC00870)。
文摘Copper is one of the most efficient catalysts widely investigated in electrochemical CO_(2) reduction, however, the further development of copper-based catalysts is constrained by severe stability problems. In this work, we developed a method for the synthesis of highly ordered Cu Au intermetallic nanoalloys(o-CuAu) under mild conditions(< 250℃), which can convert carbon dioxide to carbon monoxide with high selectivity and can operate stably for 160 h without current decay. The improved stability is believed to be due to the increased mixing enthalpy and stronger atomic interactions between Cu and Au atoms in the intermetallic nanoalloy. In addition, XPS results, Tafel slope and in situ IR spectroscopy demonstrate that high valence gold atoms on o-CuAu surface promote the reduction of CO_(2). In contrast, the disordered CuAu nanoalloy(d-CuAu) underwent atomic rearrangement to form a Cu-rich structure on the surface, leading to reduced stability. These findings may provide insight into the rational design of stable CO_(2) RR electrocatalysts through proper structural engineering.
