Engineering of Coordination Environment and Multiscale Structure in Single-Site Copper Catalyst for Superior Electrocatalytic Oxygen Reduction

• Published in: Nano letters 2020-08, Vol.20 (8), p.6206-6214
• Main Authors: Sun, Tingting, Li, Yinlong, Cui, Tingting, Xu, Lianbin, Wang, Yang-Gang, Chen, Wenxing, Zhang, Pianpian, Zheng, Tianyu, Fu, Xianzhang, Zhang, Shaolong, Zhang, Zedong, Wang, Dingsheng, Li, Yadong
• Format: Article
• Language: English
• ISSN: 1530-6984; 1530-6992
• DOI: 10.1021/acs.nanolett.0c02677

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 (E 1/2) 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.