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

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• Nickel-based molybdates are recognized for their unique isomorphous structures.
• Electrocatalytic applications, particularly in methanol oxidation and water splitting, require efficient catalysts.

Purpose of the Study:

• To synthesize and investigate pristine NiMoO₄ and Co-doped Ni₁₋ₓCoₓMoO₄.
• To explore the structure-property relationships governing the electrocatalytic activity of these materials.
• To evaluate their performance in methanol oxidation and methanol-assisted water splitting.

Main Methods:

• Synthesis of NiMoO₄ and Ni₁₋ₓCoₓMoO₄ (specifically Ni₀.₇Co₀.₃MoO₄).
• Characterization of synthesized materials to understand structure-property correlations.
• Electrocatalytic testing for methanol oxidation and hydrogen evolution reactions, including kinetic studies.

Main Results:

• Co doping induced an optimal coexistence of α and β molybdate phases in Ni₀.₇Co₀.₃MoO₄.
• This phase coexistence resulted in lattice strain, higher Ni oxidation states, and surface oxygen vacancies.
• Ni₀.₇Co₀.₃MoO₄ exhibited enhanced electrocatalytic activity in methanol oxidation and hydrogen evolution.

Conclusions:

• The findings demonstrate the significant role of phase engineering and lattice strain in enhancing catalytic activity.
• Ni₀.₇Co₀.₃MoO₄ shows considerable promise as an efficient catalyst for electrochemical methanol upgrading coupled with water splitting.
• This research contributes to the development of sustainable energy conversion technologies.