Biochar sacrificial anode assisted water electrolysis for hydrogen production

Carbon-assisted water electrolysis uses carbon oxidation reaction replacing oxygen evolu-tion reaction to decrease the anode potential and the energy consumption for water elec-trolysis hydrogen production. However, the mass transfer between carbon particle-electrolyte-anode limits its energy saving effect. Based on the principle of self-corrosion/ oxidation of carbon-based electrode materials, the biochar sacrificial anode was proposed and investigated to solve the mass transfer issue in carbon slurry assisted water electrolysis for hydrogen production. Results showed that the activity and stability of sacrificial anode could be improved simultaneously in high concentration alkaline electrolyte using pinewood char as active substance, graphite as conductive agent and coal liquefying residue as binder. The biochar anode produced less oxygen than Pt anode, and the anode potential of biochar was 60-76% of that Pt anode. The application of biochar as sacrificial anode offers an in-dustrial clean, scalable and sustainable idea to obtain green hydrogen.(c) 2022 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.