Tiny high-entropy doping strategy in CoNi-based MOF catalysts for selective glycerol electrooxidation to formic acid

Glycerol oxidation reaction (GOR) has garnered significant attention as a highly attractive reaction, extensively studied for its potential to replace the oxygen evolution reaction in overall water splitting with value-added chemicals production. However, inefficient C–H activation and poor intermediate conversion severely limit their activity and product selectivity. Herein, we develop a tiny high-entropy (HE) doping strategy to construct a Cu-, Zn-, and Mo-doped CoNi-based metal organic framework-derived catalyst (CuZnMo-MOF CoNi ) for glycerol electrooxidation. HE-effects induce the electronic structure modulation of CoNi active species and accelerate the conversion of intermediates during the GOR process. CuZnMo-MOF CoNi can achieve a current density of 10 mA cm −2 at 1.25V vs. RHE, and exhibited the highest formic acid Faradaic efficiency (92.4%) at 1.4 V vs. RHE, featuring better GOR performance compared with undoped counterparts. Moreover, the assembled membrane electrode assembly (MEA) demonstrated stable operation exceeding 120 h at a current density of 50 mA cm −2 , indicating its practical applicability. Our work establishes a tiny high-entropy doping strategy that synergistically regulates the electronic structure of active sites to optimize the reaction kinetics and selectivity during biomass electro-upgrading processes. Tiny high-entropy treatment induced electronic modulation of the catalytic Co/Ni sites in glycerol oxidation electrocatalyst, which optimizes glycerol adsorption and promotes selective C–H activation, leading to high Faradaic efficiency of formic acid (FA). Download: Download high-res image (175KB) Download: Download full-size image