Surface Selenium Coating Promotes Selective Methanol-to-Formate Electrooxidation on Ni₃Se₄ Nanoparticles

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• The transition from fossil fuels necessitates clean energy technologies.
• Cost-effective catalysts from abundant materials are crucial for sustainable energy solutions.
• Efficient electrocatalysts are needed for reactions like methanol oxidation.

Purpose of the Study:

• To develop a novel electrocatalyst for methanol oxidation reaction (MOR).
• To synthesize selenium-coated nickel selenide (Ni3Se4) nanoparticles using a facile hydrothermal method.
• To investigate the catalytic performance and understand the mechanism of the synthesized electrocatalyst.

Main Methods:

• One-step hydrothermal synthesis of Ni3Se4 nanoparticles with amorphous selenium coating.
• Electrochemical characterization, including chronoamperometry and cyclic voltammetry.
• Density functional theory (DFT) calculations to elucidate the reaction mechanism.

Main Results:

• Optimized Se-coated Ni3Se4 nanoparticles achieved a high current density of 160 mA cm-2 at 1.6 V for MOR.
• Demonstrated high methanol-to-formate Faradaic efficiency (>97.8%).
• Exhibited excellent long-term stability with <20% current decay after 18 hours.

Conclusions:

• The Se-coated Ni3Se4 nanoparticles are highly efficient electrocatalysts for methanol oxidation.
• DFT calculations reveal that SeO2 recombination lowers the energy barrier for methanol dehydrogenation.
• This work offers a promising pathway for developing advanced catalysts for clean energy applications.