Enhancing Resistance to Chloride Corrosion by Controlling the Morphologies of PtNi Electrocatalysts for Alkaline Seawater Hydrogen Evolution.

A solvothermal method to prepare PtNi alloys that have differing morphologies is described. By adjusting the feed ratio of Pt and Ni precursors in this process, PtNi alloys with different compositions (Pt : Ni atomic ratio from 1 : 3 to 3 : 1) and morphologies (evolution from nanobranches to nanoparticles) are generated. The prepared Pt48 Ni52 alloy, which has a composite morphology comprised of nanobranches and nanoparticles, exhibits superior activity and durability towards the hydrogen evolution reaction (HER) in seawater compared to those of commercial Pt/C catalyst and other PtNi alloys that have different compositions and morphologies. The excellent seawater HER performance of Pt48 Ni52 is ascribed to its nanobranch/nanoparticle morphology that optimally facilitates electron accumulation on Pt, which enhances resistance to chloride corrosion in seawater.