Abstract: Herein, Pd nanoparticles loaded Co₃O₄ catalysts (Pd@Co₃O₄) are constructed from zeolitic imidazolate framework-67 (ZIF-67) for the ethanol oxidation reaction (EOR). It is demonstrated for the first time that the electrochemical conversion of Co₃O₄ support would result in the charge distribution alignment at the Pd/Co₃O₄ interface and induce the formation of highly reactive Pd-O species (PdO*), which can further catalyze the consequent reactions of the intermediates of the ethanol oxidation. The catalyst, Pd@Co₃O₄-450, obtained under the optimized conditions exhibits excellent EOR performance with a high mass activity of 590 mA mg^-1, prominent operational stability, and extraordinary capability for the electro-oxidation of acetaldehyde intermediates. Importantly, the detailed mechanism investigation reveals that Pd@Co₃O₄-450 could be benefit to the C-C bond cleavage to promote the desirable C1 pathway for the ethanol oxidation reaction. The present strategy based on the metal-support interaction of the catalyst might provide valuable inspiration for the design of high-performing catalysts for the ethanol oxidation reaction.

Key words: ZIF-67 derived Co₃O₄, Reactive PdO* species, Mesoporous hollow structure, Ethanol electro-oxidation, Acetaldehyde electro-oxidation