Electrocatalytic CO₂ reduction to formate by a cobalt phosphino-thiolate complex

Area of Science:

• Electrochemistry
• Catalysis
• Renewable Energy Storage

Background:

• Electrochemical conversion of CO2 is a key strategy for storing renewable energy.
• Selectivity challenges and H2 byproduct formation limit current CO2 reduction methods.

Purpose of the Study:

• To investigate the activity of a cobalt phosphino-thiolate complex, [Co(triphos)(bdt)]+, for selective CO2 reduction.
• To understand the catalytic mechanism and long-term stability of the complex.

Main Methods:

• Electrochemical reduction of CO2 using the [Co(triphos)(bdt)]+ complex.
• Long-term electrolysis experiments (up to 24 hours).
• Chemical reduction studies and computational analysis.

Main Results:

• High selectivity (up to 94%) for formate production from CO2 reduction.
• Stable performance with negligible current degradation over 24 hours.
• Evidence suggests a metal-hydride pathway and an ECEC mechanism.

Conclusions:

• The cobalt complex [Co(triphos)(bdt)]+ is a highly selective and stable electrocatalyst for CO2 reduction to formate.
• Deligation of a phosphine ligand likely precedes catalysis.
• The findings support a metal-hydride pathway for efficient CO2 conversion.