Cr and Nd co-doped cobalt oxide for stable proton exchange membrane water electrolysis

Developing noble-metal-free electrocatalyst for oxygen evolution reaction in a proton exchange membrane water electrolyzer is a key to sustainable and economical hydrogen production. Herein, we rationally design and develop a chromium and neodymium co-doped cobalt oxide (CrNd-Co3O4) electrocatalyst that exhibits high activity and durability in the acidic oxygen evolution reaction condition. Furthermore, an in-situ acid circulation strategy is proposed to tackle the ubiquitous issue of membrane poisoning by leached cations in proton exchange membrane water electrolyzers. Consequently, the proton exchange membrane water electrolyzer with CrNd-Co3O4 anode achieves a stable operating current density of 2 amperes per square centimeter at 2.27 volts and 4 amperes per square centimeter at 2.54 volts for 1,000 hours. Developing noble-metal-free electrocatalysts for acidic water electrolysis is vital for hydrogen production. The authors design a Cr and Nd co-doped Co3O4 anode catalyst with enhanced activity and durability and introduce an in-situ acid circulation strategy to mitigate membrane poisoning.