Cu-based electrocatalysts derived from copper oxide exhibit good electrocatalytic activity and selectivity in the electrocatalytic nitrate reduction reaction(NO_(3)RR).However,the origin of the enhanced selectivity an...Cu-based electrocatalysts derived from copper oxide exhibit good electrocatalytic activity and selectivity in the electrocatalytic nitrate reduction reaction(NO_(3)RR).However,the origin of the enhanced selectivity and activity of NO_(3)RR is unclear.Herein,we investigate the activity of three copper oxide/hydroxidederived catalysts,and verify the phase changes during the reduction process through electrochemical in situ Raman spectroscopy.Our results show that all phases ultimately transform into metallic copper during the electrochemical synthesis process,supporting that the zero valent copper phase is the actual active phase.The high-density grain boundaries and defects are responsible for the activity of NO_(3)RR.By combining with the nickel oxide,the selectivity of the catalyst for NO_(3)RR can be further improved,achieving an ammonia Faradaic efficiency of~96% and an ammonia yield of 3.2 mmol cm^(-2)h^(-1)at -0.05 V_(RHE).This experimental design of oxygen intercalation/elimination brings a more flexible electrode,which provides a new methodology for constructing the grain boundary toward NO_(3)RR.展开更多
基金supported by the National Science and Technology Major Project(2022YFA1205200)the National Natural Science Foundation of China(22269016,22479083,22405138)the Group Project of Developing Inner Mongolia through Talents from the Talents Work Leading Group under the CPC Inner Mongolia Autonomous Regional Committee(2025TYL03)。
文摘Cu-based electrocatalysts derived from copper oxide exhibit good electrocatalytic activity and selectivity in the electrocatalytic nitrate reduction reaction(NO_(3)RR).However,the origin of the enhanced selectivity and activity of NO_(3)RR is unclear.Herein,we investigate the activity of three copper oxide/hydroxidederived catalysts,and verify the phase changes during the reduction process through electrochemical in situ Raman spectroscopy.Our results show that all phases ultimately transform into metallic copper during the electrochemical synthesis process,supporting that the zero valent copper phase is the actual active phase.The high-density grain boundaries and defects are responsible for the activity of NO_(3)RR.By combining with the nickel oxide,the selectivity of the catalyst for NO_(3)RR can be further improved,achieving an ammonia Faradaic efficiency of~96% and an ammonia yield of 3.2 mmol cm^(-2)h^(-1)at -0.05 V_(RHE).This experimental design of oxygen intercalation/elimination brings a more flexible electrode,which provides a new methodology for constructing the grain boundary toward NO_(3)RR.
