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
Alloy nanostructures have been extensively exploited in both thermal and electrochemical catalysis due to their beneficial“synergetic effects”and being cost-effective.Understandings of the alloy nanostructures inclu...Alloy nanostructures have been extensively exploited in both thermal and electrochemical catalysis due to their beneficial“synergetic effects”and being cost-effective.Understandings of the alloy nanostructures including phases,interfaces,and chemical composition are prerequisites for utilizing them as efficient electrocatalysts.Here,we use carbon-supported CuAu nanoparticles as a model catalyst to demonstrate the phase-separation induced variation of electrochemical performance for the CO_(2)reduction reaction.Driven by thermal oxidation,the CuOx phase gradually separates from the original CuAu nanoparticles,and different carbon supports,i.e.,graphene vs.carbon nanotube lead to a reversed trend in the selectivity towards CO production.Through detailed structural and chemical analysis,we find the extent of phase separation holds the key to this variation and could be used as an effective method to tune the electrochemical properties of the alloy phase.展开更多
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.
基金support from the National Natural Science Foundation of China(No.22172110)。
文摘Alloy nanostructures have been extensively exploited in both thermal and electrochemical catalysis due to their beneficial“synergetic effects”and being cost-effective.Understandings of the alloy nanostructures including phases,interfaces,and chemical composition are prerequisites for utilizing them as efficient electrocatalysts.Here,we use carbon-supported CuAu nanoparticles as a model catalyst to demonstrate the phase-separation induced variation of electrochemical performance for the CO_(2)reduction reaction.Driven by thermal oxidation,the CuOx phase gradually separates from the original CuAu nanoparticles,and different carbon supports,i.e.,graphene vs.carbon nanotube lead to a reversed trend in the selectivity towards CO production.Through detailed structural and chemical analysis,we find the extent of phase separation holds the key to this variation and could be used as an effective method to tune the electrochemical properties of the alloy phase.
