Recent Advancements in Electrode Materials for Hydrogen Production via Hydrogen Sulfide (H2S) Electrolysis

The production of green hydrogen via aqueous electrolysis of hydrogen sulfide (H2S) holds significant potential to address challenges related to sustainable energy generation and environmental protection. The electrocatalytic splitting of water polluted with highly toxic H2S is attractive for industrial applications because the process: (i) is less power-consuming than direct thermal H2S decomposition; (ii) achieves high Faradaic efficiencies for hydrogen production; and (iii) yields elemental sulfur as an added-value by-product. This review covers a brief discussion on sulfide-containing water sources and electrochemical methods for hydrogen production from H2S, specifically Direct, Indirect, and Electrochemical Membrane Reactor (EMR) systems. To become commercially and economically attractive, these approaches require improvements in electrolysis efficiency through the development of low-cost electrode materials that are resistant to sulfur poisoning and corrosion, while possessing high catalytic activity, enhanced stability, and durability. Early research focused on carbon-based materials combined with noble metal oxides, transition metal compounds, and related materials. Since their practical performance is limited, investigations have shifted toward nanostructured electrocatalysts with unique crystal structures and designs, which show significantly improved efficiency for H2S electrolysis. This review highlights the potential of H2S electrolysis for hydrogen production, giving special attention to recent advancements in electrode materials.