Manipulating local coordination of copper single atom catalyst enables efficient CO2-to-CH4 conversion
Yizhou Dai, Huan Li, Chuanhao Wang, Weiqing Xue, Menglu Zhang, Donghao Zhao, Jing Xue, Jiawei Li, Laihao Luo, Chunxiao Liu, Li Xu, Peixin Cui, Qiu Jiang, Tingting Zheng, Songqi Gu, Yao Zhang, Jianping Xiao, Chuan Xia, Jie Zeng
Abstract
Abstract Electrochemical CO 2 conversion to methane, powered by intermittent renewable electricity, provides an entrancing opportunity to both store renewable electric energy and utilize emitted CO 2 . Copper-based single atom catalysts are promising candidates to restrain C-C coupling, suggesting feasibility in further protonation of CO* to CHO* for methane production. In theoretical studies herein, we find that introducing boron atoms into the first coordination layer of Cu-N 4 motif facilitates the binding of CO* and CHO* intermediates, which favors the generation of methane. Accordingly, we employ a co-doping strategy to fabricate B-doped Cu-N x atomic configuration (Cu-N x B y ), where Cu-N 2 B 2 is resolved to be the dominant site. Compared with Cu-N 4 motifs, as-synthesized B-doped Cu-N x structure exhibits a superior performance towards methane production, showing a peak methane Faradaic efficiency of 73% at −1.46 V vs . RHE and a maximum methane partial current density of −462 mA cm −2 at −1.94 V vs . RHE. Extensional calculations utilizing two-dimensional reaction phase diagram analysis together with barrier calculation help to gain more insights into the reaction mechanism of Cu-N 2 B 2 coordination structure.