Wide-pH-range adaptable ammonia electrosynthesis from nitrate on Cu-Pd interfaces

作     者：Yongtao Wang Peng Zhang Xiaoyun Lin Gong Zhang Hui Gao Qingzhen Wang Zhi-Jian Zhao Tuo Wang Jinlong Gong 

作者机构：Key Laboratory for Green Chemical Technology of Ministry of EducationSchool of Chemical Engineering and TechnologyTianjin UniversityTianjin 300072China Collaborative Innovation Center of Chemical Science and EngineeringTianjin 300072China Haihe Laboratory of Sustainable Chemical TransformationsTianjin 300192China Joint School of National University of Singapore and Tianjin UniversityInternational Campus of Tianjin UniversityBinhai New CityFuzhou 350207China 

出 版 物：《Science China Chemistry》 (中国科学（化学英文版）)

年 卷 期：2023年第66卷第3期

页      面：913-922页

核心收录：

学科分类：08[工学] 080502[工学-材料学] 0805[工学-材料科学与工程（可授工学、理学学位）] 

基　　金：supported by the National Key R&D Program of China(2021YFA1500804) the National Natural Science Foundation of China(22121004,51861125104) the Natural Science Foundation of Tianjin City(18JCJQJC47500) Haihe Laboratory of Sustainable Chemical Transformations,the Program of Introducing Talents of Discipline to Universities(BP0618007)and the Xplorer Prize 

主　　题：nitrate reduction ammonia synthesis Cu-Pd interfaces reaction kinetics break p H limitation 

摘      要：Ammonia production via electrochemical nitrate reduction is essential for environmental protection and the emerging hydrogen economy. Complex nitrate wastewater with a wide pH range calls for flexible catalysts with high selectivity. A high Faradaic efficiency(FE) of NH3 cannot be obtained under strong acid or alkaline conditions due to the uncontrollable adsorption energy and coverage of hydrogen species(H*) on active sites. This article describes the design and fabrication of a copper-palladium(Cu-Pd) alloy nanocrystal catalyst that inhibits H2 and nitrite generation in electrolytes with different nitrate concentrations and varied pH. The interfacial sites of Cu-Pd alloys could enhance the adsorption energy and coverage of H* while increasing the reaction rate constant of NO_(2)*-to-NO*, which achieves a rapid conversion of NO_(2)* along with a decreased FE of NO_(2)-. Under ambient conditions, optimal FE(NH3) is close to 100% at a wide pH range, with the solar-to-chemical conversion efficiency approaching 4.29%. The combination of thermodynamics and kinetics investigations would offer new insights into the reduction mechanism of NO_(2)* for further development of nitrate reduction.