Molecular electrocatalysts can mediate fast, selective CO₂ reduction in a flow cell

Area of Science:

• Electrochemistry
• Catalysis
• Materials Science

Background:

• Electrochemical carbon dioxide (CO2) conversion is crucial for sustainable chemical production.
• Solid-state catalysts face challenges in maintaining high selectivity and efficiency at high current densities for CO2 reduction reaction (CO2RR).
• Molecular catalysts offer design flexibility for selectivity and low overpotentials but typically operate at low current densities unsuitable for commercial applications.

Purpose of the Study:

• To investigate the potential of molecular catalysts for efficient CO2 conversion at industrially relevant current densities.
• To demonstrate high selectivity and efficiency using a molecular catalyst under demanding operating conditions.

Main Methods:

• Utilized cobalt phthalocyanine, a molecular catalyst, in a zero-gap membrane flow reactor.
• Operated the electrochemical cell at current densities of 150 milliamperes per square centimeter (mA/cm2).
• Analyzed the product selectivity of the CO2 reduction reaction (CO2RR).

Main Results:

• Cobalt phthalocyanine mediated CO2 to CO formation with selectivities exceeding 95% at 150 mA/cm2.
• Achieved efficient CO2 conversion using a molecular catalyst under high current density conditions.
• Demonstrated that molecular catalysts can be effective in practical CO2RR applications.

Conclusions:

• Molecular catalysts, specifically cobalt phthalocyanine, can achieve high selectivity and efficiency in CO2 conversion at high current densities.
• This finding presents a novel strategy for optimizing CO2 reduction reaction (CO2RR) catalysts and electrolyzer designs.
• Highlights a promising direction for advancing electrochemical CO2 conversion technologies for commercial viability.