Highly selective and corrosion resistant interconnected pNiCo@NF electrocatalysts for methanol-assisted seawater electrolysis

Seawater electrolysis for hydrogen production is emerging as a key technology for sustainable energy solutions. However, the primary challenge lies in the competition between the oxygen evolution reaction (OER) and the chlorine evolution reaction (CER) at the anode, both of which exhibit slow kinetics. This work demonstrates an organic-oxidation-assisted strategy that employs the thermodynamically favorable selective methanol oxidation reaction (SMOR) to inhibit the undesirable OER/CER using porous NiCo bimetallic foams (pNiCo@NF) as electrocatalysts, enabling the simultaneous production of hydrogen and valuable formate with significantly reduced energy consumption. The as prepared electrode, with Ni:Co ratio of 1:1, required an overpotential of 87 mV @ 20 m A cm⁻² for hydrogen evolution reaction (HER). This catalyst also excelled in SMOR and OER, requiring 1.38 V and 1.54 V @ 50 mA cm⁻², implying that SMOR required less potential than OER to achieve the same current density along with the production of value-added formate. The integrated two-electrode system using pNiCo@NF bifunctional electrocatalysts exhibited enhanced electrocatalytic activity for methanol assisted seawater electrolysis with low cell voltage of 1.43 V @ 20 mA cm⁻², requiring 190 mV less cell voltage than seawater electrolysis. The findings of this study provide a facile approach for energy-efficient production of hydrogen from seawater.