Corrosion-Resistant Nickel/Carbonate Hydroxide-Based Electrocatalysts for Efficient Hydrogen Production via Direct Seawater Electrolysis (RIP2026-00059)

Ahmadyar Qureshi

The increasing global scarcity of freshwater resources challenges the long-term viability of conventional water electrolysis for large-scale hydrogen production. Direct seawater electrolysis (DSE) offers a more sustainable alternative; however, the high chloride content and biological impurities typical of natural seawater significantly compromise electrode stability, accelerate corrosion, and hinder catalytic performance. To address these limitations, this study focuses on designing corrosion-resistant, electrocatalysts capable of efficient operation under alkaline seawater conditions. Nickel foam was selected as the conductive substrate and was modified via hydrothermal synthesis with copper carbonate hydroxide (CuCH), molybdenum carbonate hydroxide (MoCH), and a bimetallic copper–molybdenum carbonate hydroxide (CuMoCH). These carbonate–hydroxide phases can play dual roles: (i) suppressing chloride-induced degradation through localized alkalinity modulation and (ii) enhancing HER activity by promoting water dissociation and strengthening hydrogen adsorption. Incorporating Mo further contributes to corrosion resistance and improves electronic conductivity. To simulate realistic yet controlled seawater conditions, natural seawater was blended with 1 M KOH to form an alkaline, anion-rich electrolyte. Electrochemical testing in a standard three-electrode configuration (working: modified Ni foam; counter: graphite; reference: Ag/AgCl) showed that CuCH-modified electrodes achieved an overpotential as low as 153 mV at 10 mA/cm² for the hydrogen evolution reaction (HER). Enhanced charge-transfer kinetics and reduced interfacial impedance were consistently observed through CV, LSV, and EIS analyses. Ongoing testing of MoCH and CuMoCH is expected to yield comparable HER performance while offering superior corrosion resistance and long-term durability. Current findings demonstrate that carbonate–hydroxide surface engineering of nickel foam is a promising approach to stabilizing electrodes for DSE under alkaline seawater environments. Future work should prioritize scale-up of synthesis, systematic durability testing, and achieving stable operation at industrial current densities in unmodified natural seawater.