High‐Density‐Cluster Ru Catalyst Substitute for Pt/C Benchmark Improves Membrane Water Electrolysis

Abstract

ABSTRACT The hydrogen evolution reaction (HER) is of great importance for the renewable energy conversion to hydrogen fuel via water electrolysis. However, the current benchmark Pt/C catalyst suffers from high cost, pH sensitivity, and deficient durability, severely restricting the large‐scale development of membrane water electrolysis. Herein, we develop a cost‐effective Pt‐free catalyst featuring high‐density, ultrafine Ru nanoclusters modified with CoP and uniformly dispersed on nitrogen‐doped carbon films (NCF). This catalyst achieves not only superior HER activity across a wide pH range but also robust stability at ampere‐level large current densities, manifesting as a competitive alternative to commercial Pt/C. Typically, Ru‐CoP/NCF exhibits an overpotential of only 22 mV at 10 mA cm −2 in acidic media, with the mass activity and price activity 1.21 and 2.18 times higher than Pt/C, respectively. A proton exchange membrane water electrolyzer using Ru‐CoP/NCF catalyst delivers a high current density of 1.0 A cm −2 at a voltage of merely 1.67 V and sustains long‐term operation for 780 h with a minimal decay rate of 84 µV h −1 . This Ru‐CoP/NCF catalyst thus demonstrates practical potential for the development of non‐Pt membrane electrodes.