Electrocatalytic CO₂ Reduction with a Half-Sandwich Cobalt Catalyst: Selectivity towards CO

Area of Science:

• Inorganic Chemistry
• Electrochemistry
• Catalysis

Background:

• Electrocatalytic CO2 reduction is crucial for sustainable energy and chemical production.
• Cobalt-based catalysts are promising for CO2 conversion, but selectivity remains a challenge.
• Half-sandwich Cp*Co(III) complexes offer tunable electronic properties for catalytic applications.

Purpose of the Study:

• To develop a novel Cp*Co(III)-half-sandwich catalyst for electrocatalytic CO2 reduction.
• To investigate the catalyst's performance in aqueous acetonitrile solution.
• To understand the role of the ligand design in CO2 reduction selectivity.

Main Methods:

• Synthesis and characterization of a Cp*Co(III) complex with a proton-responsive N,N-bidentate ligand.
• Electrocatalytic CO2 reduction experiments using controlled-potential electrolysis.
• Analysis of product distribution (CO vs. HCOOH) and Faradaic efficiency.

Main Results:

• The catalyst selectively produced CO as the major product, unlike similar known catalysts that favor HCOOH.
• Achieved a Faradaic efficiency of approximately 70% for CO production.
• Determined an overpotential of 0.78 V for CO production.

Conclusions:

• The designed Cp*Co(III) catalyst effectively promotes CO2 reduction to CO with high selectivity.
• The electron-rich cobalt center and proton-responsive ligand facilitate CO2 activation and proton transfer.
• This system offers a promising alternative for selective CO production from CO2 electroreduction.