Modulating the Surface Electronic Structure of Pt With Co ₂ P for Effective Methanol Oxidation Reaction and Hydrogen Evolution Reaction Under Acidic and Alkaline Conditions

ABSTRACT To develop cost‐effective and high‐performance water splitting electrocatalysts, precise modulation of the electronic structure of platinum (Pt) active sites is crucial. Herein, a Pt@Co ₂ P/Co/CNF heterojunction catalyst is fabricated via electrospinning, phosphorization, and in situ replacement. DFT calculations confirm that the heterojunction interface induces charge redistribution at Pt sites, which, together with Co ₂ P‐mediated electronic regulation of Pt for balanced intermediate adsorption and accelerated water dissociation and the enhanced structural stability and inhibited Pt aggregation from the Co/CNF framework, synergistically lowers the reaction energy barrier. Consequently, the catalyst exhibits superior bifunctional performance with low hydrogen evolution reaction (HER) overpotentials of 16 mV (alkaline) and 32 mV (acidic) at 10 mA cm ⁻² , high methanol oxidation reaction (MOR) mass activities of 2082 and 2326 mA mg _Pt ⁻¹ in corresponding media, and outstanding 100 h stability. This work provides a feasible strategy for designing acid‐alkali compatible bifunctional electrocatalysts.