电催化CO_(2)还原立方体Cu_(2)O催化剂的制备及其在大面积膜电极反应器中的应用

Preparation of cubic Cu_(2)O catalyst for electrocatalytic CO_(2)reduction and its application in a large-area membrane electrode reactor

电化学二氧化碳还原反应(carbon dioxide reduction reaction,CO_(2)RR)产乙烯目前已成为电催化CO_(2)RR领域的研究重点和热点.通过简单的化学沉淀耦合化学还原保护法成功获得了富含(111)晶面的立方体结构Cu_(2)O催化剂,系统研究了其在H型反应器以及零间距膜电极组件(membrane electrode assembly,MEA)反应器中的电化学性能.结果表明.富含(111)晶面的立方体结构Cu_(2)O催化剂表现出了优异的产乙烯活性;相比于H型反应器,零间距MEA反应器进行CO_(2)RR时的最佳法拉第效率(Faradaic efficiency,FE)提升了13.94%,总电流密度也基本可以满足工业化的需求(>200 mA/cm^(2));设计并组装的大面积(25 cm^(2))零间距MEA反应器在CO_(2)RR中表现出了优异的催化性能,且在槽压大于2.9 V时表现出了独特的“面积效应”.“面积效应”的出现表明零极距MEA反应器在有效面积放大时,除电极面积、电解质浓度、CO_(2)流速等关键因素的调控外,极板的流道设计、导电性优化等均可能会影响催化反应的电流密度.

The application of electrochemical carbon dioxide reduction reaction(CO_(2)RR)to produce ethylene has attracted much research interest in thefield of electrocatalytic CO_(2)RR.A cubic Cu_(2)O catalyst with abundant(111)crystal faces was successfully pre-pared by a simple chemical precipitation coupled chemical reduction protection method.In addition,electrochemical properties of cubic Cu_(2)O catalysts in an H-type reactor and zero-gap membrane electrode assembly(MEA)reactor were systematically studied.The results revealed several points.First,the Cu_(2)O catalyst with abundant(111)crystal faces showed excellent ethylene production capabilities.Second,when compared with H-type reactor,the optimal Faradaic efficiency(FE)of zero-gap MEA reactor for CO_(2)RR was increased by 13.94%,and its total current density satisfied industrialization requirements(>200 mA/cm^(2)).In addition,the large-area(25 cm^(2))zero-gap MEA reactor was designed and assembled in this work,and results showed the excellent catalytic performance at CO_(2)RR and a unique“area effect”above 2.9 V.The appearance of the“area effect”indi-cates that the current density of the catalytic reaction may be affected by the plate channel design and conductivity optimization in addition to the adjustment of the electrode area,electrolyte concentration,CO_(2)flow rate and other key factors when the effective area of the zero-gap MEA reactor is enlarged.