Carbon promoted water electrolysis to produce hydrogen at room temperature

Abstract

The objective of the work was to conduct water electrolysis at room temperature with reduced energy costs for hydrogen production. The electrochemical gasification of carbons consumes only 9.6 kcal/mol H 2 O compared to 56.7 kcal/molH 2 O for conventional water electrolysis. In this work, carbon-assisted hydrogen production and the reaction energetics/kinetics at applied potentials |E 0 | between 0.1 and 1.8 V are studied. The carbon promoted water electrolysis could be performed at applied potentials as low as |E 0 |=0.21 V as opposed to conventional water electrolysis which requires |E 0 |>1.25 V. The study reveals that the H 2 produced per W h is higher at the lower voltages, but longer times are required to produce the same amount of H 2 .The following parameters were considered for evaluating the process: time taken, potential applied, current required and amount of carbon to be added. Based on such an evaluation, practical parameters of |E 0 | ~ 0.5 V and carbon concentration (0.08 g/cm 3) are suggested.