Engineering Low‐Coordinated Edge and Step Sites on Ultrathin PdSn Nanomesh for Promoting C─C Bond Cleavage of Ethanol Oxidation Reaction

Promoting C─C bond cleavage of ethanol to achieve a complete 12-electron pathway (C1 pathway) for ethanol oxidation reaction (EOR) is crucial for the development of highly efficient direct ethanol fuel cells. In this study, a highly porous ultrathin PdSn nanomesh (NM) with high proportion of low-coordinated edge and step sites is developed for alkaline EOR. The PdSn NM/C catalyst exhibited superior specific activity of 21.9 ± 0.9 mA cm^-2 _Pd with a significantly enhanced Faradaic efficiency of C1 pathway to CO₂. In situ attenuated total reflection surface enhanced infrared absorption spectroscopy measurements demonstrated the significant enhancement of C1 selectivity on PdSn NM/C. Theoretical calculations further revealed the pivotal role of low-coordinated edge and step sites in effectively lowering the activation energy barrier for C─C bond cleavage of CH₃CO*. This work provides a strategy for the rational design of highly efficient EOR electrocatalysts through low-coordinated site engineering.