Interstitial Pt–Pd Bimetallic Sites Enable Cooperative Intermediate Regulation for Methanol-Assisted Hydrogen Generation

Methanol-assisted hydrogen generation reduces energy consumption while maintaining high hydrogen productivity. However, constructing bifunctional catalysts with high hydrogen evolution reaction (HER) activity, CO tolerance, and long-term stability remains challenging. Here, we develop Pt–Pd bimetallic sites anchored on WCN in which the interstitial site between Pt and Pd atoms optimizes H* adsorption to accelerate HER and modulates HCO* adsorption to promote the HCOOH* formation pathway, thereby suppressing CO poisoning during the methanol oxidation reaction (MOR). Electronic coupling optimizes H* adsorption and promotes charge redistribution, delivering a HER overpotential of 43 mV, a Tafel slope of 59.6 mV dec⁻¹, and sustained stability over 400 h. Meanwhile, the synergetic Pt–Pd configuration enhances CO* tolerance and achieves a mass activity of 5.57 A mg_PtPd⁻¹, 10.0 times higher than commercial Pt/C with stable performance retained over 60,000 s. When PtPd WCN serves as both anode and cathode in a MOR||HER flow cell, it requires a low voltage of 0.58 V at 10 mA cm⁻² and delivers stable operation for over 250 h. This work establishes an atomic-level strategy for designing bifunctional catalysts, providing a pathway toward energy-efficient methanol-assisted hydrogen generation.