MoS2-based materials as alternative cathode catalyst for PEM electrolysis

Pt and Ir are the most popular catalysts for electrochemical water splitting, but their low abundance on Earth's crust and high price render them unsustainable for future use. In the quest for alternative catalyst materials, a popular hydro-treating catalyst, molybdenum disulphide (MoS2), has been found to be promising for hydrogen evolution reaction (HER). Two types of MoS2-carbon composites, (i) physical mixture of MoS2 and carbon black (Vulcan (R)) and (ii) MoS2 supported on reduced graphene oxide (RGO), were examined. Among the MoS2-based materials tested, 47 wt% MoS2/Vulcan (R) gave the best performance in terms of current density at an encouraging level for practical application. The poor performance of bare MoS2 was attributed to its poor electrical conductivity. No indication of performance deterioration was observed for 18 h of continuous operation at 2.0 V cell voltage with 47 wt% MoS2/Vulcan (R). MoS2/RGO hybrids showed HER activity, which was considerably higher than that of bare MoS2. Copyright (C) 2014, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.