Electrochemical biomass upgrading on CoOOH nanosheets in a hybrid water electrolyzer

Electrocatalytic water splitting is a promising route for green hydrogen production. However, the anodic reaction of oxygen evolution has a high overpotential and low value products are obtained. Therefore, the exploration of decoupling hydrogen evolution and oxygen evolution and coupling with a value-added anodic reaction has received tremendous attention. Herein, we employ an in situ electrochemical anion-oxidation strategy to synthesize cobalt oxyhydroxide (CoOOH) nanosheets from cobalt carbonate hydroxide nanoarrays. With the use of CoOOH nanosheets as the anodic electrocatalyst in a hybrid water electrolyzer with 5-hydroxymethylfurfural, a high value product of 2,5-furandicarboxylic acid can be produced on the anode with ∼100% conversion, ∼100% selectivity and ∼100% Faraday efficiency at an operating voltage as low as 1.423 V. CoOOH nanosheets synthesized by an in situ electrochemical anion-oxidation strategy were used as anodic catalysts in a hybrid water electrolyzer.