(688g) Green H2 Production through Biochar Advanced Water Electrolysis

Gaseous hydrogen (H₂), as a fuel, is a most promising energy source to replace non-renewable fossil fuel energy sources and will play an essential character in the greener future. High-grade H₂ could be produced by a water electrolysis process in which water converts into hydrogen and water through an electrochemical route. The water electrolysis process needs 1.23 V cell potential to break water into hydrogen and oxygen molecules. The water electrolysis supported on biochar oxidation takes only 0.23 V cell potential, which is six times lower than the simple water electrolysis. There are several advantages to using BAWE to produce green hydrogen; (i) biochar has more significant electrochemical activity than graphite and carbon black; (ii) it has a high surface area of >500 m²/g without any treatment, which also has one of the reasons for its significant electrochemical reactivity; (iii) it is operated at <100 ℃ and ambient pressure which is different from conventional biochar gasification process; (iv) the anodic and cathodic product, i.e., CO₂ and H₂, respectively, could be further used for methanol production; and (v) there are different types of the biomass available like bagasse, corn stover, animal manure, etc., which could be utilized to synthesize biochar for BAWE process. In this work, a different source of biochar was utilized for BAWE to produce green H₂. The electrolysis of biochar-mediated electrolytes was performed at 1 V at different operating conditions, like electrolysis with and without biochar at different temperatures and chlorinated mediums. The faradic efficiencies were calculated for the anodic and cathodic products, which were oxygenated hydrocarbons and hydrogen gas, respectively. Biochar was characterized before and after electrolysis to compare the electrochemical reactivity, efficiency, and durability of the biochar. The oxygenated hydrocarbons were identified by HPLC analysis and will also be reported as a part of this work.