Electron‐deficient ZnO induced by heterointerface engineering as the dominant active component to boost CO<sub>2</sub>‐to‐formate conversion
Qing Qin, Zijian Li, Yingzheng Zhang, Haeseong Jang, Li Zhai, Liqiang Hou, Xiaoqian Wei, Zhe Wang, Min Gyu Kim, Shangguo Liu, Xien Liu
Abstract
Abstract Electrocatalytic CO 2 ‐to‐formate conversion is considered an economically viable process. In general, Zn‐based nanomaterials are well‐known to be highly efficient electrocatalysts for the conversion of CO 2 to CO, but seldom do they exhibit excellent selectivity toward formate. In this article, we demonstrate that a heterointerface catalyst ZnO/ZnSnO 3 with nanosheet morphology shows enhanced selectivity with a maximum Faradaic efficiency (FE) of 86% at −0.9 V versus reversible hydrogen electrode and larger current density for the conversion of CO 2 to formate than pristine ZnO and ZnSnO 3 . In particular, the FEs of the C 1 products (CO + HCOO − ) exceed 98% over the potential window. The experimental measurements combined with theoretical calculations revealed that the ZnO in ZnO/ZnSnO 3 heterojunction delivers the valence electron depletion and accordingly optimizes Zn d ‐band center, which results in moderate Zn–O hybridization of HCOO* and weakened Zn–C hybridization of competing COOH*, thus greatly boosting the HCOOH generation. Our study highlights the importance of charge redistribution in catalysts on the selectivity of electrochemical CO 2 reduction.