Highly Efficient Oxygen‐Modulated Ru‐Based HER Electrocatalyst in a Wide pH Range

Abstract Crystallized Ruthenium (Ru) metal with high hydrogen production activity is extremely unstable. Herein, we report an efficient and durable hydrogen evolution reaction (HER) electrocatalyst Ru‐MC (mesoporous carbon) synthesized by a special method, in which Ru 3+ is added after the formation of spherical MC, leading to only a small amount of Ru being embedded and the vast majority being evenly distributed on the MC surface. The dispersed Ru nanoparticles not only prevent them from aggregation to greatly improve their stability (both over 160 hours in acidic and alkaline solutions), but also provide outstanding intrinsic catalytic activity because oxygen regulates the electronic structure of Ru nanoparticles. The as‐synthesized catalyst only needs an overpotential of 27 and 40 mV to deliver 10 mA cm −2 in 1.0 M KOH and 0.5 M H 2 SO 4 . The present work provides guidance for the design of efficient and stable Ru‐based HER electrocatalysts used in a wide pH range.