Lattice Strain Mediated Reversible Reconstruction in CoMoO₄·0.69H₂O for Intermittent Oxygen Evolution

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• Heterogeneous interfaces are crucial for modulating electrocatalyst performance and durability.
• The exact mechanisms governing phase evolution and their correlation with activity in hybrid electrocatalysts remain unclear.

Purpose of the Study:

• To investigate the phase evolution kinetics at the CoMoO₄·0.69H₂O/Co₃O₄ interface.
• To understand the role of lattice strain in oxygen evolution reaction (OER) catalysis.

Main Methods:

• Configuration of a CoMoO₄·0.69H₂O/Co₃O₄ heterogeneous interface.
• In situ Raman spectroscopy to monitor phase transformations.
• Theoretical calculations to assess reaction energy barriers.

Main Results:

• Lattice strain (3.31%) in CoMoO₄·0.69H₂O, inherited from the inert Co₃O₄ support, dictates the activity of the reconstructed CoOOH.
• Reversible conversion between active CoOOH and amorphous cobalt oxide was observed during OER under applied potentials.
• The hybrid catalyst demonstrated superior durability with negligible decay over 10 cycles.

Conclusions:

• Lattice strain significantly enhances OER performance by optimizing intermediate adsorption and reducing reaction energy barriers.
• The findings provide insights into designing durable and efficient electrocatalysts through controlled interface engineering.