Metal-support interaction of Ru nanoparticle and NiCo2O4 support for enhanced oxygen evolution reaction

Spherical Ru-NiCo 2 O 4  synthesized by hydrothermal-calcination formed Ru-O-Co/Ni bonds to enhance metal-support interaction. • The nanowire-assembled ball-like structure exposed abundant active sites and accelerated mass transfer. • Metal-support interaction effect optimized electronic structure, downshifted d-band center, and regulated intermediate adsorption. • Ru-NiCo 2 O 4  exhibited outstanding OER activity with an overpotential of 217 mV at 10mA/cm² and durable stability over 70 h. Hydrogen production by water electrolysis is a promising approach for renewable energy conversion, yet its efficiency is severely restricted by the sluggish oxygen evolution reaction (OER). Ru-based catalysts exhibit outstanding OER activity but suffer from poor stability and high cost. Constructing metal-support interaction (MSI) is an effective strategy to optimize the electronic structure and stability of Ru catalysts. Herein, fluffy spherical Ru anchored on NiCo 2 O 4 was fabricated via hydrothermal and calcination processes, in which Ru O Co/Ni bridge bonds were formed to strengthen the MSI effect between Ru nanoparticle and NiCo 2 O 4 support. The unique nanowire-assembled ball-like structure exposed abundant active sites and accelerated mass transfer. The MSI effect regulated the electronic structure, derived directional interfacial electron transfer, downshifted the d-band center, and optimized intermediate adsorption for OER. The synthesized Ru-NiCo 2 O 4 catalyst exhibited an overpotential of 217 mV at the current density of 10 mA/cm 2 and a long-term stability of 70 h.