Defective Bimetallic Selenides for Selective CO₂ Electroreduction to CO

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• CO2 electroreduction (CO2 RR) to CO is crucial for carbon cycling but faces challenges.
• Gold (Au) is highly selective for CO2 RR but prohibitively expensive for industrial use.

Purpose of the Study:

• To develop a cost-effective catalyst with gold-like selectivity for CO2 RR.
• To investigate the catalytic properties of bimetallic CuInSe2, particularly with selenium vacancies.

Main Methods:

• Computational analysis of orbital interactions and adsorption strengths.
• Electrochemical testing of Se-defective CuInSe2 (V-CuInSe2) in aqueous electrolyte.
• Performance evaluation of V-CuInSe2 in an aqueous Zn-CO2 cell.

Main Results:

• Bimetallic CuInSe2 exhibits moderate adsorption of CO2 RR intermediates, favoring the reaction pathway.
• Hydrogen evolution is energetically unfavorable on CuInSe2 due to surface reconstruction.
• Se vacancies in CuInSe2 optimize the CO2 RR pathway, leading to high CO selectivity comparable to noble metals.
• V-CuInSe2 demonstrates satisfactory performance in a Zn-CO2 battery.

Conclusions:

• Designing cost-effective catalysts with noble-metal-like properties is a viable strategy for efficient electrocatalysts.
• Transition bimetallic selenides, like V-CuInSe2, show significant promise as active and economical electrocatalysts for CO2 conversion.