Engineering Lattice Strain in Co-Doped NiMoO4 for boosting Methanol Oxidation Reaction.

Nickel-based molybdates have attracted considerable attention owing to their distinctive isomorphous structure. In this study, pristine NiMoO4 and Co-doped Ni1-xCoxMoO4 were synthesized and investigated for their electrocatalytic activity in methanol oxidation and methanol-assisted water splitting reactions. Through a comprehensive exploration of the structure-property relationship, it was found that the optimal coexistence of α and β molybdate phases, induced by Co doping, led to lattice strain and facilitated the presence of essential catalytic descriptors such as higher oxidation states of Ni and surface oxygen vacancies within the lattice. These factors contributed to the enhanced electrocatalytic activity of Ni0.7Co0.3MoO4 in methanol oxidation and hydrogen evolution reaction. Detailed kinetic studies were conducted to further elucidate the mechanisms involved. Overall, these findings highlight the promising potential of Ni0.7Co0.3MoO4 as an effective catalyst for electrochemical methanol upgrading in conjunction with water splitting, with implications for sustainable energy conversion technologies.