Liquid Metal Dynamic Interface Enabled Reverse Hydrogen Spillover Boosting Electrocatalytic Nitrate Reduction
Wenda Chen, Wei Zeng, Zanyu Chen, Yixiao Zou, Chen Zhang, Shenghua Ye, Jia Ding, Xiaopeng Han, Wenbin Hu
Abstract
Abstract Electrochemical nitrate reduction (NO 3 − RR) to ammonia involves intricate and sluggish proton‐coupled electron transfer (PCET) pathways, the active hydrogen (H*) flux regulation are crucial for its efficiency. Here, we demonstrate a liquid metal‐based catalyst, Co@Ga, featuring a dynamic liquid Ga core–solid Co shell interface under operando conditions. This unique architecture enables an unprecedented reverse hydrogen spillover mechanism, where H* generated via facile water dissociation on liquid Ga support spontaneously migrates to adjacent metallic Co for efficient hydrogenation of adsorbed nitrate/intermediates. Moreover, the strong electron donation from Ga to Co also accelerates the rate‐determining NO 3 − → NO 2 − step through a three‐step relay mechanism. Consequently, the synergy of these effects endows Co@Ga with exceptional NO 3 − RR performance, achieving an ultra‐high NH 3 yield rate of 51 mol h −1 g Co −1 , Faraday efficiency of 94.5% at −0.3 V versus RHE, and outstanding stability over 400 h at 1 A cm −2 in a membrane electrode. This work presents the concept of dynamic liquid‐solid‐liquid interfaces for reversing conventional hydrogen spillover, offering a universal strategy to regulate multi‐proton/electron transfers in complex electrocatalytic reactions.