Evaluation of low-cost cathode catalysts for high yield biohydrogen production in microbial electrolysis cell.

As an ideal fuel due to the advantages of no pollution, high combustion heat and abundant sources, hydrogen gas can be produced from organic matter through the electrohydrogenesis process in microbial electrolysis cells. But in many MECs, platinum is often used as catalyst, which limits the practical applications of MECs. To reduce the cost of the MECs, Ni-based alloy cathodes were developed by electrodepositing. In this paper hydrogen production using Ni-W-P cathode was studied for the first time in a single-chamber membrane-free MEC. At an applied voltage of 0.9 V, MECs with Ni-W-P cathodes obtained a hydrogen production rate of 1.09 m3/m3/day with an cathodic hydrogen recovery of 74%, a Coulombic efficiency of 56% and an electrical energy efficiency relative to electrical input of 139%, which was the best result of reports in this study. The Ni-W-P cathode demonstrated a better electrocatalytic activity than the Ni-Ce-P cathode and achieved a comparable performance to the Pt cathode in terms of hydrogen production rate, Coulombic efficiency, cathodic hydrogen recovery and electrical energy efficiency at 0.9 V.