Building a Heterostructure between Ni Nanoparticles and Ni₃Mo₃N to Enhance the Activity of the Hydrogen Oxidation Reaction in Alkaline Medium

The development of efficient nonprecious metal catalysts for the alkaline hydrogen oxidation reaction (HOR) catalyst in alkaline anion-exchange membrane fuel cells (AEMFCs) is of great significance. Nickel-based catalysts are considered to be promising HOR catalysts. Here, we report the interfacial engineering of reduced graphene oxide-supported Ni and Ni-Mo bimetallic nitrides (Ni-Ni3Mo3N/rGO), which exhibit excellent catalytic activity of alkaline HOR. The electron transfer from Ni to Ni3Mo3N has been regulated to tune the electronic structure. Due to the interface effect between Ni and Ni3Mo3N, Ni-Ni3Mo3N/rGO exhibits enhanced HOR activity, with a high current density of 2.65 mA cm-2 at an overpotential of 50 mV. Additionally, it demonstrates higher exchange current density (j0, 3.21 mA cm-2) and kinetic current density (jk, 10.35 mA cm-2), indicating fast kinetics and high intrinsic activity of Ni-Ni3Mo3N/rGO. Furthermore, detailed characterization results illustrate that due to the rational adsorption of hydrogen and hydroxyl groups by Ni-Ni3Mo3N/rGO, it possesses significant activity and durability. These research findings are of great importance for the development of more efficient alkaline HOR catalysts to promote the application of alkaline AEMFCs.