Tuning <i>D</i> ‐Band Electronic Interaction Between Pt and Ru Confined in Fullerene Network Accelerate Hydrogen Spillover for Efficient and pH‐Universal Hydrogen Evolution

Abstract Hydrogen spillover on metal‐supported electrocatalysts can largely impact the catalytic activity in the hydrogen evolution reaction (HER). However, the insightful understanding on the mechanism at the metal‐metal interface is limited, and the relevant exploration on the electronic structure is scarce. Here, it is unveiled that the hydrogen spillover takes place at the interface of PtM (M═Fe, Co, Ni) and Ru via tuning their d ‐band electronic structures. Narrowing the d ‐band center difference (∆ ɛ d ) between PtM and Ru reduces the energy barrier for hydrogen spillover. Specifically, the PtNi/Ru catalyst with optimized ∆ ɛ d exhibits outstanding HER activity, that is, requiring an overpotential of 25 and 29 mV to achieve a current density of 10 mA cm −2 in 1 m KOH and 0.5 m H 2 SO 4 , respectively. Various in situ /operando spectroscopic measurements uncover the hydrogen adsorption and desorption behaviors on the PtNi/Ru, accounting for the accelerated interfacial hydrogen spillover. Theoretical calculation result discloses that the tailorable d ‐band electronic structure of PtNi/Ru facilitates the hydrogen adsorption/desorption and water dissociation process, resulting in the boosted electrocatalytic HER performance.