Surface Area‐Enhanced Cerium and Sulfur‐Modified Hierarchical Bismuth Oxide Nanosheets for Electrochemical Carbon Dioxide Reduction to Formate
Naveenkumar Palanimuthu, Mohan Raj Subramaniam, Muthu Austeria P, Preetam K. Sharma, Vinoth Ramalingam, Karthik Peramaiah, S. Ramakrishnan, Geun Ho Gu, Eileen Hao Yu, Dong Jin Yoo
Abstract
Abstract Electrochemical carbon dioxide reduction reaction (ECO 2 RR) is a promising approach to synthesize fuels and value‐added chemical feedstocks while reducing atmospheric CO 2 levels. Here, high surface area cerium and sulfur‐doped hierarchical bismuth oxide nanosheets (Ce@S‐Bi 2 O 3 ) are develpoed by a solvothermal method. The resulting Ce@S‐Bi 2 O 3 electrocatalyst shows a maximum formate Faradaic efficiency (FE) of 92.5% and a current density of 42.09 mA cm −2 at −1.16 V versus RHE using a traditional H‐cell system. Furthermore, using a three‐chamber gas diffusion electrode (GDE) reactor, a maximum formate FE of 85% is achieved in a wide range of applied potentials (−0.86 to −1.36 V vs RHE) using Ce@S‐Bi 2 O 3 . The density functional theory (DFT) results show that doping of Ce and S in Bi 2 O 3 enhances formate production by weakening the OH* and H* species. Moreover, DFT calculations reveal that *OCHO is a dominant pathway on Ce@S‐Bi 2 O 3 that leads to efficient formate production. This study opens up new avenues for designing metal and element‐doped electrocatalysts to improve the catalytic activity and selectivity for ECO 2 RR.