Surficial-enriched Ru on octahedral CeO2 with strong electronic interactions as an efficient electrocatalyst for hydrogen generation in alkaline freshwater/seawater

Abstract

Developing high-performance and cost-effective electrocatalysts for the hydrogen evolution reaction (HER) is highly essential for the large-scale application of water splitting. In this work, surficial-enriched ruthenium (Ru) catalyst was developed on octahedral cerium dioxide (CeO₂) through a combination of hydrothermal synthesis and ultrafast (60 s) wet impregnation approaches, utilizing H₂O₂ as a facilitator (Ru/CeO₂–H₂O₂). Experimental characterization and density functional theory (DFT) calculation demonstrate that the created oxygen vacancy (Ov) and strong electronic interactions play crucial roles in improving catalytic activity and stability. In particular, the specific octahedral morphology and surficial-enriched Ru enhance the exposure of abundant active sites, thereby accelerating the reaction kinetics. The as-synthesized Ru/CeO₂–H₂O₂ demonstrated commendable catalytic performance in both 1 M KOH and 1 M KOH + seawater with small overpotentials of 37 and 47 mV, respectively, to attain a current density of 10 mA cm⁻². Furthermore, it exhibited remarkable long-term stability at both 10 mA cm⁻² and 500 mA cm⁻², and demonstrated the ability to drive overall water splitting when coupled with sustainable energy sources. Therefore, this study presents a promising approach for constructing high noble-metal utilization efficiency with a specific support, offering potential for enhanced sustainable energy applications.