Synergistic Effect of Grain Boundaries and Oxygen Vacancies on Enhanced Selectivity for Electrocatalytic CO <sub>2</sub> Reduction
Xiaoqian Wei, Zijian Li, Haeseong Jang, Zhe Wang, Xuhao Zhao, Yunfei Chen, Xuefeng Wang, Min Gyu Kim, Xien Liu, Qing Qin
Abstract
Abstract Dual‐engineering involved of grain boundaries (GBs) and oxygen vacancies (V O ) efficiently engineers the material's catalytic performance by simultaneously introducing favorable electronic and chemical properties. Herein, a novel SnO 2 nanoplate is reported with simultaneous oxygen vacancies and abundant grain boundaries (V,G‐SnO x /C) for promoting the highly selective conversion of CO 2 to value‐added formic acid. Attributing to the synergistic effect of employed dual‐engineering, the V,G‐SnO x /C displays highly catalytic selectivity with a maximum Faradaic efficiency (FE) of 87% for HCOOH production at −1.2 V versus RHE and FEs > 95% for all C 1 products (CO and HCOOH) within all applied potential range, outperforming current state‐of‐the‐art electrodes and the amorphous SnO x /C. Theoretical calculations combined with advanced characterizations revealed that GB induces the formation of electron‐enriched Sn site, which strengthens the adsorption of *HCOO intermediate. While GBs and V O synergistically lower the reaction energy barrier, thus dramatically enhancing the intrinsic activity and selectivity toward HCOOH.