A CoV₂O₄ precatalyst for the oxygen evolution reaction: highlighting the importance of postmortem electrocatalyst...

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• Vanadium-doped cobalt oxides are explored as catalysts for the oxygen evolution reaction (OER).
• Doping aims to tune electronic structure and stabilize intermediates in crystalline cobalt spinel materials.

Purpose of the Study:

• To synthesize and evaluate CoV2O4 as a catalyst for the oxygen evolution reaction.
• To investigate the true active species in vanadium-doped cobalt oxide catalysts through postmortem analysis.

Main Methods:

• Synthesis of CoV2O4 material.
• Electrocatalytic testing for oxygen evolution reaction.
• Postmortem characterization of the catalyst material.

Main Results:

• The synthesized CoV2O4 exhibited good activity for the oxygen evolution reaction.
• Postmortem analysis revealed vanadium dissolution, leaving an amorphous CoOx material.
• The vanadium-free amorphous CoOx, not the original CoV2O4, was identified as the active catalytic species.

Conclusions:

• The active catalyst for the oxygen evolution reaction in this system is an amorphous, vanadium-free cobalt oxide.
• Postmortem characterization is crucial for accurate mechanistic and computational studies of such catalytic materials.
• Rethinking catalyst design to account for in-situ transformation is necessary.