In Situ Electrochemical Reconstruction of PtCu Alloy to Pt Cluster/CuOOH Interface for Boosted 5‐Hydroxymethylfurfural Electro‐Oxidation

ABSTRACT Real‐time monitoring of structural evolution and identification of intrinsic active sites during electrocatalysis are vital to the rational design of high‐performance electrocatalysts. Herein, PtCu bimetallic alloy electrocatalyst is synthesized for the electrochemical 5‐hydroxymethylfurfural oxidation reaction (HMFOR). The electrochemical results show that the obtained electrocatalyst delivers superior activity and selectivity toward HMFOR with suppressed side reactions. In situ Raman and synchrotron x‐ray absorption fine structure characterizations are employed to investigate structural evolution and the electrocatalytic mechanism. Characterization results confirm that the original alloy phase is not the real active site. Driven by anodic potential, Pt─Cu bonds breakage, metallic copper is oxidized into CuOOH, and separated Pt atoms aggregate into clusters. Strong metal‐support interaction forms via Pt─O linkage, constructing a reactive Pt cluster/CuOOH interface. The theoretical calculations demonstrate that the interfacial synergy optimizes intermediate adsorption, accelerates charge transfer, lowers free energy barrier, thus boosting catalytic kinetics. This work reveals the electrochemical reconstruction behavior and structure‐performance relationship of bimetallic catalysts, offering a feasible strategy for designing advanced electrocatalysts for biomass conversion.