Preferential Cation Vacancies in Perovskite Hydroxide for the Oxygen Evolution Reaction

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• The oxygen evolution reaction (OER) is crucial for energy conversion technologies.
• Defect engineering is a key strategy to enhance catalyst performance.
• Selective generation of cation vacancies in catalysts remains challenging.

Purpose of the Study:

• To investigate the selective generation of tin (Sn) vacancies in SnCoFe perovskite hydroxide.
• To elucidate the structure-activity relationship of Sn vacancies in OER.
• To enhance the electrocatalytic activity for OER.

Main Methods:

• Utilized Ar plasma treatment for defect engineering.
• Employed X-ray absorption spectra (XAS) to confirm Sn vacancy formation.
• Characterized the resulting catalyst for OER performance.

Main Results:

• Successfully generated abundant Sn vacancies on the SnCoFe perovskite hydroxide surface.
• Confirmed preferential Sn vacancy formation due to lower lattice energy.
• Observed promotion of active CoFe site exposure and formation of an amorphous surface layer.
• Demonstrated modulated conductivity and enhanced OER performance.

Conclusions:

• Selective generation of Sn vacancies is achievable using Ar plasma.
• Sn vacancies play a critical role in enhancing OER activity by modifying catalyst structure and electronic properties.
• This work provides insights into cation vacancy engineering for advanced electrocatalysts.