Ru doping triggering reconstruction of cobalt phosphide for coupling glycerol electrooxidation with seawater electrolysis

Abstract

Seawater electrolysis is a promising approach for sustainable energy without relying on precious freshwater. However, the large-scale seawater electrolysis is hindered by low catalytic efficiency and severe anode corrosion caused by the harmful chlorine. In contrast to the oxygen evolution reaction (OER) and chlorin ion oxidation reaction (ClOR), glycerol oxidation reaction (GOR) is more thermodynamically and kinetically favorable alternative. Herein, a Ru doping cobalt phosphide (Ru-CoP₂) is proposed as a robust bifunctional electrocatalyst for seawater electrolysis and GOR, for the concurrent productions of hydrogen and value-added formate. The in situ and ex situ characterization analyses demonstrated that Ru doping featured in the dynamic reconstruction process from Ru-CoP₂ to Ru-CoOOH, accounting for the superior GOR performance. Further coupling GOR with hydrogen evolution was realized by employing Ru-CoP₂ as both anode and cathode, requiring only a low voltage of 1.43 V at 100 mA cm⁻², which was 250 mV lower than that in alkaline seawater. This work guides the design of bifunctional electrocatalysts for energy-efficient seawater electrolysis coupled with biomass resource upcycling.