Engineering of Coordination Environment and Multiscale Structure in Single-Site Copper Catalyst for Superior Electrocatalytic Oxygen Reduction
Tingting Sun, Yinlong Li, Tingting Cui, Lianbin Xu, Yang‐Gang Wang, Wenxing Chen, Pianpian Zhang, Tianyu Zheng, Xianzhang Fu, Shaolong Zhang, Zedong Zhang, Dingsheng Wang, Yadong Li
Abstract
Herein, we report efficient single copper atom catalysts that consist of dense atomic Cu sites dispersed on a three-dimensional carbon matrix with highly enhanced mesoporous structures and improved active site accessibility (Cu-SA/NC(meso)). The ratio of +1 to +2 oxidation state of the Cu sites in the Cu-SA/NC(meso) catalysts can be controlled by varying the urea content in the adsorption precursor, and the activity for ORR increases with the addition of Cu1+ sites. The optimal Cu1+-SA/NC(meso)-7 catalyst with highly accessible Cu1+ sites exhibits superior ORR activity in alkaline media with a half-wave potential (E1/2) of 0.898 V vs RHE, significantly exceeding the commercial Pt/C, along with high durability and enhanced methanol tolerance. Control experiments and theoretical calculations demonstrate that the superior ORR catalytic performance of Cu1+-SA/NC(meso)-7 catalyst is attributed to the atomically dispersed Cu1+ sites in catalyzing the reaction and the advantage of the introduced mesoporous structure in enhancing the mass transport.