In-Situ Constructing Oxide-Anion Dual-Layer on Ce-B-Containing Electrode Electrolyte Interface Towards Highly Corrosive Seawater Splitting

Abstract

Seawater electrocatalysis is a promising technology for sustainable energy production, but the challenge of electrode corrosion by chloride ions is urgently needed to be addressed. Herein, a Ce-B-containing electrode was found to activate an in-situ evolutionary oxide (CeO2)-anion (B(OH)4-) dual-layer during the electrocatalytic reconstruction process, effectively resisting the invasion of chloride ions. In detail, a Ni-Fe-Ce-B electrode exhibits high hydrogen and oxygen evolution activity with only 160 and 271 mV overpotentials at 100 mA cm-2 in 1 M KOH + 0.5 M NaCl, and superior stability with slight overpotential loss after over 100 h at industrial current density ~ 0.5 A cm-2 at 1.817 V for alkaline natural seawater splitting. Comparative experiments indicating that existing alkaline electrocatalysts can be adjusted to withstand rigorous seawater conditions through straightforward modifications. This work reveals a novel evolutionary oxide-anion dual-layer protection mechanism to effectively prevent chloride ion corrosion in highly corrosive seawater splitting.

Keywords: Seawater electrocatalysis, Boride, Dual-layer protection, Anti-corrosion, Chloride ion