Alloyed Pt Single-Atom Catalysts for Durable PEM Water Electrolyzer

The high cost of noble metals is one of the key factors hindering the large-scale application of proton exchange membrane (PEM) water electrolyzer for hydrogen production. Recently, single-atom catalysts (SACs) with a potential of maximum atom utilization efficiency enable lowering the metal amount as much as possible; unfortunately, their durability remains a challenge under PEM water electrolyzer working conditions. Herein, a highly-stable alloyed Pt SAC is demonstrated through a plasma-assisted alloying strategy and applies to a PEM water electrolyzer. In this catalyst, single Pt atoms are firmly anchored onto a Ru support via a robust metal–metal bonding strength, as evidenced by these complementary characterizations. This SAC is used in a PEM water electrolyzer system to achieve a cell voltage as low as 1.8 V at 1000 mA cm−2. Impressively, it can operate over 1000 h without obvious decay, and the catalyst is present in the form of individual Pt atoms. To the knowledge, this will be the first SAC attempt at a cell level toward long-term PEM. This work paves the way for designing durable SACs employed in the actual working condition in the PEM water electrolyzer.