Selective Loading of Atomic Platinum on a RuCeOx Support Enables Stable Hydrogen Evolution at High Current Densities.

High‐performance electrocatalysts for the hydrogen evolution reaction (HER) have an important role to play in the development of renewable energy. Platinum remains the most efficient known HER electrocatalyst. Therefore, it is necessary to find ways to maximize Pt utilization in actual practical applications. Herein we demonstrate a facile strategy for synthesizing RuCeOx‐supported, selectively loaded, atomic Pt (0.49 wt. %) (denoted Pt/RuCeOx‐PA) by photoactivation at ambient temperature and pressure. Through the photoelectron transfer at the Mott‐Schottky heterojunction in RuCeOx, Pt atoms became embedded into the RuO2 lattice. The resulting selectively loaded Pt‐O‐Ru moieties in Pt/RuCeOx‐PA give a stronger hydrogen spillover effect than Pt complexes randomly loaded by either chemical activation or thermal activation. As a result, Pt/RuCeOx‐PA shows superior HER performance to the materials prepared by random loading and is even better than a commercial Pt/C catalyst with much higher Pt loading (20 wt. %) at high current densities (from 50–600 mA cm−2). [ABSTRACT FROM AUTHOR]