物理化学学报2023，Vol.39Issue(2)：100-108,9.DOI:10.3866/PKU.WHXB202207026
富氧空位的非晶氧化铜高选择性电催化还原CO2制乙烯
Oxygen Vacancy-Rich Amorphous Copper Oxide Enables Highly Selective Electroreduction of Carbon Dioxide to Ethylene
摘要
Abstract
The ever-increasing carbon dioxide(CO2)emissions caused by excessive fossil fuel consumption induce environmental issues such as global warming.To overcome this,the electrocatalytic CO2 reduction(ECR)under ambient conditions offers an appealing approach for converting CO2 to value-added chemicals and realizing a closed carbon loop.Among the ECR products,ethylene(C2H4),an important building block for plastics and other chemicals,has attracted considerable attention owing to its compatibility with existing infrastructure and the promising substitution of industrial steam cracking.In recent years,numerous efforts have been devoted to developing highly active and selective catalysts for converting CO2 to C2H4,with most studies having focused on Cu-based materials.Despite the significant advancements made to date,the development of the ECR-to-C2H4 process is still hindered by the lack of suitable catalysts that can effectively activate CO2 and strengthen the surface binding of*CO and*COH species.In this study,an amorphous copper oxide(CuOx)nanofilm that is rich in oxygen vacancies was prepared via a facile vacuum evaporation method for the efficient electrocatalytic conversion of CO2 to C2H4.It was expected that the nano-scale electrode thickness would greatly accelerate charge-and mass-transfer during CO2 electrolysis.Moreover,the introduction of oxygen vacancies favored the adsorption of CO2 and intermediates.As a result,in a typical H-cell,the synthesized defective catalyst delivered a maximum Faradaic efficiency of 85％±3％at-1.3 V versus the reversible hydrogen electrode and maintained a stable C2H4 selectivity over 48 h in a 0.1 M potassium bicarbonate solution.Interestingly,the performance observed with the synthesized electrocatalyst in this study is comparable with that of state-of-the-art Cu-based ECR catalysts.Additional structural and chemical characterizations confirmed the robust nature of the as-prepared catalyst.Moreover,when the catalyst was utilized in a membrane electrode assembly cell,it achieved a maximum C2H4 partial current density of approximately 115.4 mA·cm-2 at a cell voltage of-1.95 V and Faradaic efficiency of 78％±2％at a cell voltage of-1.75 V.Furthermore,theoretical and experimental analyses revealed that oxygen defects not only favored CO2 adsorption but also enabled strong affinities for*CO and*COH intermediates,which synergistically contributed to a high selectivity for C2H4 formation.We believe that our present work will motivate the exploration of amorphous Cu-based materials for achieving efficient CO2-to-C2H4 electrolysis and be a guide towards fundamentally understanding the mechanism of catalytic CO2 reduction.关键词
二氧化碳固定/二碳产物/电催化/非晶催化剂/铜氧化物Key words
CO2 fixation/C2 product/Electrocatalysis/Amorphous catalyst/Cu oxide分类
化学化工引用本文复制引用
韦天然,张书胜,刘倩,邱园,罗俊,刘熙俊..富氧空位的非晶氧化铜高选择性电催化还原CO2制乙烯[J].物理化学学报,2023,39(2):100-108,9.基金项目
The project was supported by the National Natural Science Foundation of China(22075211,21601136,51971157,51621003),and Tianjin Science Fund for Distinguished Young Scholars(19JCJQJC61800).国家自然科学基金(22075211,21601136,51971157,51621003),天津市杰出青年科学基金(19JCJQJC61800)资助项目 （22075211,21601136,51971157,51621003）
