Size‐Dependent Selectivity of Electrochemical CO<sub>2</sub> Reduction on Converted In<sub>2</sub>O<sub>3</sub> Nanocrystals
Yang Huang, Xinnan Mao, Guotao Yuan, Duo Zhang, Binbin Pan, Jun Deng, Yunru Shi, Na Han, Chaoran Li, Liang Zhang, Lu Wang, Lin He, Youyong Li, Yanguang Li, Yanguang Li, Yanguang Li
Abstract
Abstract The size modulation of catalyst particles represents a useful dimension to tune catalytic performances by impacting not only their surface areas but also local electronic structures. It, however, has remained inadequately explored and poorly elucidated. Here, we report the interesting size‐dependent selectivity of electrochemical CO 2 reduction on In 2 O 3 nanocrystals. 5‐nm nanoparticles and 15‐nm nanocubes with focused size distribution are prepared via a facile solvothermal reaction in oleylamine by carefully controlling a set of experimental parameters. They serve as the precatalysts, and are reduced to In nanocrystals while largely inherit the original size feature during electrochemical CO 2 reduction. Catalyst derived from 15‐nm nanocubes exhibits greater formate selectivity (>95 %) at lower overpotential and negligible side reactions compared to bulk‐like samples (indium foil and 200‐nm cubes) as well as the catalyst derived from smaller 5‐nm nanoparticles. This unique size dependence is rationalized as a result of the competition among different reaction pathways by our theoretical computations. Smaller is not always better in the catalyst design.