Copper-iron-molybdenum mixed oxides as efficient oxygen evolution electrocatalysts

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• Developing efficient electrocatalysts for the oxygen evolution reaction (OER) is crucial for electrochemical energy conversion technologies.
• Ternary mixed oxides offer tunable properties for enhanced catalytic performance.

Purpose of the Study:

• To synthesize and characterize ternary Cu, Fe, and Mo mixed oxides (CuxFe2-x(MoO4)3) for OER electrocatalysis.
• To investigate the effect of copper substitution on the structural and electrocatalytic properties of Fe2(MoO4)3.

Main Methods:

• Co-precipitation method for oxide synthesis.
• Characterization using FT-IR, XRD, XPS, and TEM.
• Electrochemical evaluation via anodic polarization and Tafel slope analysis in alkaline media.

Main Results:

• CuxFe2-x(MoO4)3 oxides were successfully prepared with varying copper content (0 ≤ x ≤ 1.5).
• Crystallinity was monoclinic for oxides with x ≤ 1.
• Optimal copper addition (x=1) enhanced OER activity by approximately 50 times compared to Fe2(MoO4)3.
• Excessive copper (x=1.5) reduced catalytic activity.

Conclusions:

• Ternary Cu-Fe-Mo mixed oxides are promising electrocatalysts for OER.
• Copper substitution significantly influences the electrocatalytic performance, with an optimal concentration for enhanced activity.
• Electrode kinetic parameters suggest specific reaction mechanisms for the oxygen evolution reaction.