Unraveling the interfacial effect of PdBi bimetallic catalysts on promoting CO2 electroreduction to formate
Wenhui Liu, Lingtong Ding, Minmin Liu, Xiao Wang, Zhengrong Zhang, Tian‐Wen Jiang, Shengjuan Huo, Wen‐Bin Cai
Abstract
Through interface engineering and content control strategy, a PdBi bimetallic interface structure was constructed for the first time to selectively convert CO 2 to formate with a remarkably high Faraday efficiency (FE formate ) of 94% and a partial current density ( j formate ) of 34 mA·cm − 2 at −0.8 V vs. reversible hydrogen electrode (RHE) in an H-cell. Moreover, the PdBi interface electrocatalyst even exhibited a high current density of 180 mA·cm − 2 with formate selectivity up to 92% in a flow cell and could steadily operate for at least 20 h. Electrochemical in-situ attenuated total reflection surface enhanced infrared absorption spectroscopy (ATR-SEIRAS) confirmed that the PdBi interface could greatly weaken the adsorption of *CO intermediates due to electronic and geometric effects. Density functional theory (DFT) calculations also established that the PdBi interface regulated the CO 2 -to-formate pathway by reducing the energy barrier toward HCOOH and largely weakening the adsorption of *CO intermediates on the catalyst surface. This study reveals that the unique PdBi bimetallic interface can provide a novel platform to study the reaction mechanism through combining in-situ ATR-SEIRAS and DFT calculations.