A Self-Supported Coral-like Pt/SnO₂/Nb₂O₅/Nb Electrode: A Bifunctional Electrocatalyst for Membrane-Free Green H₂ Production via Coupling Ethanol Selective Electrooxidation

The production of green hydrogen via water electrolysis faces challenges due to the sluggish oxygen evolution reaction at the anode. In this study, we developed a self-supported bifunctional Pt/SnO₂/Nb₂O₅/Nb electrocatalyst capable of coupling the hydrogen evolution reaction to the selective ethanol oxidation reaction (EOR) in an acidic medium. The catalyst demonstrated efficacy for the EOR, with an <i>E</i> _onset of +130 mV versus SHE results in a peak current density of 8.97 mA cm^-2. The bifunctional electrocatalyst exhibited a spontaneous and rapid increase in current for the HER, achieving an overpotential of -48 mV for a current density of 5 mA cm^-2 and a Faradaic efficiency of 99.7%. This efficient coupling of the EOR with the HER reduces energy consumption for green hydrogen generation compared to traditional water splitting. With hydrogen being the sole gaseous product, the HER-EOR electrolysis system can operate effectively without a membrane, promising a more cost-effective, sustainable, and efficient green hydrogen production.