ZIF-8-Derived Dodecahedral NiCo Nanostructure for Energy-Efficient Methanol-Assisted Seawater Electrolysis

Methanol-assisted seawater electrolysis is a potent technology for producing green hydrogen while simultaneously upgrading methanol into value-added formate. However, the practical application of this hybrid process is hindered by the lack of efficient and durable bifunctional electrocatalysts capable of simultaneously driving the methanol oxidation reaction (MOR) and hydrogen evolution reaction (HER) in chloride-rich electrolytes. Herein, we have synthesized a bimetallic ZIF-8-derived electrocatalyst (NiCo-ZIF8-P950) via a simple one-pot method followed by high-temperature pyrolysis. The optimized NiCo-ZIF8-P950 catalyst retained the characteristic ZIF-8 dodecahedral morphology with the uniform dispersion of ultrafine Ni–Co nanoparticles embedded in a conductive N-doped porous carbon matrix. Benefiting from this favorable architecture and bimetallic synergy, NiCo-ZIF8-P950 exhibited excellent bifunctional activity for both the MOR and HER in alkaline seawater electrolytes. Notably, the catalyst required only 113 and 130 mV to achieve 20 mA cm –2 for HER in simulated and natural seawater, respectively. When applied to methanol-assisted seawater electrolysis, the NiCo-ZIF8-P950||NiCo-ZIF8-P950 cell achieved 50 mA cm –2 at a low voltage of 1.45 V, outperforming conventional seawater electrolysis (1.66 V). Furthermore, this system demonstrated long-term durability and efficient formate generation, offering a promising approach for energy-efficient hydrogen production from seawater.