Electron Redistribution of Ru Site on MoO 2 @NiMoO 4 Support for Efficient Ampere-Level Current Density Electrolysis of Alkaline Seawater.

Seawater electrolysis is a promising but challenging strategy to generate carbon-neutral hydrogen. A grand challenge for hydrogen evolution reaction (HER) from alkaline seawater electrolysis is the development of efficient and stable electrocatalysts to overcome the limitation of sluggish kinetics. Here, a 3D nanorod hybrid catalyst is reported, which comprises heterostructure MoO 2 @NiMoO 4 supported Ru nanoparticles (Ru/ MoO 2 @NiMoO 4 ) with a size of ≈5 nm. Benefitting from the effect of strongly coupled interaction, Ru/MoO 2 @NiMoO 4 catalyst exhibits a remarkable alkaline seawater hydrogen evolution performance, featured by a low overpotential of 184 mV at a current density of 1.0 A cm -2 , superior to commercial Pt/C (338 mV). Experimental observations demonstrate that the heterostructure MoO 2 @NiMoO 4 as an electron-accepting support makes the electron transfer from the Ru nanoparticles to MoO 2 , and thereby implements the electron redistribution of Ru site. Mechanistic analysis elucidates that the electron redistribution of active Ru site enhances the ability of hydrogen desorption, thereby promoting alkaline seawater HER kinetics and finally leading to a satisfactory catalysis performance at ampere-level current density of alkaline seawater electrolysis.