Bifunctional Mn-doped CoSe2 nanonetworks electrode for hybrid alkali/acid electrolytic H2 generation and glycerol upgrading

Electrolytic water splitting, as a promising route to hydrogen (H2) production, is still confronted with the sluggish anodic oxygen evolution reaction (OER) and its less value-added O2 production. Herein, we report a bifunctional electrode fabricated by in situ growth of Mn-doped CoSe2 nanonetworks on carbon fiber cloth (Mn-CoSe2/CFC), which shows attractive electrocatalytic properties toward glycerol oxidation reaction (GOR) in alkali and hydrogen evolution reaction (HER) in acid. A flow alkali/acid hybrid electrolytic cell (fA/A-hEC) was then developed by coupling anodic GOR with cathodic HER with the Mn-CoSe2/CFC bifunctional electrode. Such fA/A-hEC enables a rather low voltage of 0.54 V to achieve 10 mA cm−2, and maintain long-term electrolysis stability over 300-h operation at 100 mA cm−2 with Faraday efficiencies of over 99% for H2 and 90% for formate production. The designed bifunctional electrode in such innovative fA/A-hEC device provides insightful guidance for coupling energy-efficient hydrogen production with biomass upgradation.