Boosting Alkaline Hydrogen Evolution by Pulse Joule-Heating Activated PtRu Nanoclusters on N-Doped Mesoporous Carbon

The precise construction of bimetallic sites and the regulation of interfacial environments are crucial for accelerating the sluggish kinetics of alkaline hydrogen evolution. Transient thermochemical processing provides a unique pathway to modulate heterogeneous coordination and metal–support interaction. Herein, we report a pulse Joule-heating (PJH) strategy to activate mixed-valence PtRu nanoclusters on nitrogen-doped mesoporous carbon. The resulting PtRu/NMC-JH exhibits exceptional hydrogen evolution reaction (HER) activity in 1.0 M KOH, delivering an overpotential of only 50.4 mV to reach 100 mA cm –2 and an ultralow Tafel slope of 30.8 mV dec –1, with superior stability exceeding 100 h. Furthermore, the alkaline water electrolysis (AWE) device integrated with this cathode delivers a current density of 0.5 A cm –2 at a cell voltage of 1.59 V with robust stability over 800 h. The remarkable performance enhancement is attributed to the synergy between the subnanometer cluster size and PJH-strengthened electronic coupling, which facilitates efficient charge transfer and accelerates the alkaline HER kinetics. This work highlights the potential of ultrafast thermal activation for designing small-sized clusters and tailoring interfacial chemistry for high-performance energy conversion.