Enhancing the Hydrogen Evolution Reaction Efficiency of Binary CoNi Catalysts through Controlled Pd Incorporation: Design of Ternary PdCoNi Alloy Catalysts

Water electrolysis is an effective, carbon-free process for producing clean hydrogen (H₂). However, enhancing H₂ production rates through alkaline water electrolysis poses significant challenges, particularly in developing efficient, durable, and cost-effective nonplatinum electrocatalysts for the hydrogen evolution reaction (HER). In this study, we designed binary CoNi and ternary PdCoNi alloy catalysts on nickel foam using a modified chemical vapor deposition method for the HER in 1.0 M KOH. The incorporation of 15% atomic Pd significantly enhances the catalytic performance of the binary CoNi alloy. The optimal PdCoNi alloy demonstrates exceptional catalytic metrics, including low overpotentials of 53 mV at 10 mA cm^-2 and 330 mV at 1000 mA cm^-2, a small Tafel slope of 59 mV dec^-1, and excellent durability over 24 h. This positions it as a promising alternative to commercial platinum and many other multicomponent catalysts for HER. The outstanding performance can be attributed to the synergistic interaction between Pd and CoNi, as well as the uniform distribution of active sites and the porous electrode structure, which enhance electron transfer rates and reduce hydrogen adsorption energy on the catalyst surface. The results indicate that employing an effective deposition strategy can yield robust and highly active alloys with minimal noble metal content, thereby significantly enhancing the electrocatalytic performance.