Pure hydrogen and sulfur production from H2S by an electrochemical approach using a NiCu-MoS2 catalyst

Abstract

An enormous amount of hydrogen sulfide (H2S) exists in an industrial world primarily as an undesirable waste by-product of fossil fuel processing, including natural gas, petroleum, and coal gasification, entailing a greener strategy for its conversion into more beneficial products viz. hydrogen (H2) and sulfur (S). Herein, we have formulated a cost-effective and mixed-phase (1T and 2H) micro-flower like NiCu-MoS2 catalyst towards the anodic sulfide oxidation reaction (SOR) and cathodic H2 production via electrolysis. The SOR was initiated at 0.21 V vs. RHE, which is 1.02 V inferior to the thermodynamical potential of the oxygen evolution reaction (OER), i.e. 1.23 V. Moreover, it maintains 98.1% H2 faradaic efficiency with remarkable endurance up to 150 h. Importantly when a H2S electrolyzer was fabricated with NiCu-MoS2, only 0.7 V cell potential was adequate to yield profuse H2 by H2S splitting, which is practically unachievable for water splitting due to kinetic and energetic complexity.