NiMo/C Doped with Trace Precious Metals (Pt, Rh, Ru, Ir) for Enhanced Hydrogen Evolution Reaction in Anion Exchange Membrane Water Electrolysis

Anion exchange membrane water electrolysis (AEMWE) provides a broader selection of electrocatalyst materials, including non-novel metals, due to its high pH operating condition. However, the development of transition metal-based electrocatalysts for the hydrogen evolution reaction (HER), exhibiting activity comparable to Pt/C, remains a significant challenge, aiming to reduce material costs for AEMWE. In this study, we demonstrate the remarkable activity and durability of NiMo/C electrocatalysts for HER, achieved by incorporating small amounts of precious metals (<5 at.%) such as Pt, Rh, Ru, and Ir. The effects of precious metal doping were thoroughly investigated through electrochemical and chemical state analyses. Furthermore, membrane electrode assemblies (MEAs) were fabricated using the NiMoX/C (X: precious metal) electrocatalysts, in which catalysts were coated onto membrane. Single cell tests were conducted to validate the practical feasibility of these electrocatalysts. Notably, the addition of even minute quantities of precious metals is highly effective in enhancing both the activity and stability of the HER. These findings offer valuable insights into the development of highly active HER electrocatalysts at low cost for AEMWE applications.