Harnessing the Interface Effect of Ru/CeO 2 Heterostructures for Enhanced Hydrogen Electrocatalysis in Freshwater and Seawater Electrolysis

Abstract Direct seawater electrolysis confronts pivotal challenges in both catalytic efficiency and process engineering domains. Herein, a metal hybridization strategy is proposed for crafting an HER catalyst featuring Ru nanoparticles anchored on the surface of CeO 2 and integrated with conductive carbon (Ru/CeO 2 /C). Ru/CeO 2 /C heterostructure catalyst exhibits remarkable electrocatalytic prowess towards HER, manifesting overpotentials of merely 30 mV at a current density of 10 mA cm −2 in 1 M KOH, surpassing the performance of commercial Pt/C. Notably, the overpotentials escalate to 41 and 338 mV respectively, in environments of 1 M KOH supplemented with 0.5 M NaCl and 3.5% NaCl. Meanwhile, Ru/CeO 2 /C || RuO 2 exhibits 1.68 V at 10 mA cm −2 in alkaline seawater for overall water splitting. Experimental data underscores the Ru‐CeO 2 interface's pivotal role in modulating charge, intensifying electronic coupling, and refining adsorption/desorption energies. High surface area carbon integration amplifies activity, stability, and kinetics via robust interfacial dynamics, yielding the Ru/CeO 2 /C heterostructure catalyst's remarkable hydrogen production efficiency in alkaline and seawater media. This work may provide new options for the design and preparation of potential HER directly used seawater electrocatalysts.