Enhanced CO2 electroreduction efficiency through secondary coordination effects on a pincer iridium catalyst

Area of Science:

• Catalysis
• Electrochemistry
• Organometallic Chemistry

Background:

• Electrocatalytic reduction of carbon dioxide (CO2) is crucial for sustainable energy and chemical production.
• Developing efficient and selective catalysts for CO2 conversion remains a significant challenge.

Purpose of the Study:

• To investigate the efficacy of an iridium(III) trihydride pincer complex in the electrocatalytic reduction of CO2 to formate.
• To explore the mechanistic aspects of the catalytic process, including product formation and release.

Main Methods:

• Electrochemical synthesis and characterization of the iridium(III) trihydride complex.
• Electrocatalytic CO2 reduction experiments in a water/acetonitrile mixture.
• Mechanistic studies using preliminary experiments to probe reaction steps.

Main Results:

• The iridium complex demonstrated excellent Faradaic efficiency for CO2 electroreduction to formate.
• The catalyst operated at a low overpotential, indicating high catalytic activity.
• Mechanistic insights suggest facile formate formation but a kinetically hindered product release step.

Conclusions:

• The designed iridium pincer complex is a highly effective electrocatalyst for CO2 reduction to formate.
• Understanding the product release limitation is key to further catalyst optimization for improved turnover rates.