Low-Pt Pt/NiMo-C catalysts for high-performance hydrogen evolution in anion exchange membrane water electrolysis

Abstract

The development of electrocatalysts with reduced platinum-group-metal content is crucial for advancing anion exchange membrane water electrolysis (AEMWE). Here, platinum was incorporated into a carbon-supported NiMo-derived catalyst via impregnation and reductive thermal treatment. The resulting Pt/NiMo-C contained 2.47 wt% Pt within the metallic fraction, corresponding to 0.988 wt% overall and a cathode loading of 49.4 μg Pt cm −2 . In 1.0 M KOH, the catalyst required only 45.4 mV to reach −10 mA cm −2 and exhibited a Tafel slope of 39.5 mV dec −1 , outperforming commercial 20 wt% Pt/C. Long-term stability was confirmed over 280 h of chronopotentiometry with minimal potential drift. As the cathode in a 9 cm 2 AEMWE paired with IrO 2 , Pt/NiMo-C delivered 1.0 A cm −2 at 2.18 V (1.81 V after iR correction) at 60 °C. These findings highlight Pt/NiMo-C as a promising low-Pt cathode, combining reduced noble-metal usage with competitive HER activity and AEMWE performance.