Formic Acid Electro-Synthesis by Concurrent Cathodic CO₂ Reduction and Anodic CH₃ OH Oxidation

Area of Science:

• Electrochemistry
• Catalysis
• Materials Science

Background:

• Electrochemical conversion of CO2 is crucial for mitigating climate change and utilizing emissions.
• Existing methods face challenges with slow oxygen evolution and low-value products.
• Developing efficient catalysts for CO2 reduction and alternative anodic reactions is essential.

Purpose of the Study:

• To develop an efficient strategy for formic acid synthesis via concurrent CO2 reduction and methanol oxidation.
• To investigate the performance of mesoporous SnO2 on carbon cloth (mSnO2/CC) and CuO nanosheets on copper foam (CuONS/CF) as catalysts.
• To establish a low-voltage electrolyzer for simultaneous formic acid production.

Main Methods:

• Utilized mSnO2/CC as a cathodic catalyst for CO2 reduction.
• Employed CuONS/CF as an anodic catalyst for partial methanol oxidation.
• Assembled an electrolyzer with these catalysts for concurrent reactions.

Main Results:

• Anodic CuONS/CF demonstrated significantly enhanced electro-activity at a lowered potential (1.47 V vs. RHE at 100 mA cm-2).
• Cathodic mSnO2/CC achieved a high Faraday efficiency of 81% for formic acid production from CO2 at 0.7 V vs. RHE.
• The integrated electrolyzer operated at a low cell voltage of 0.93 V at 10 mA cm-2 for formic acid synthesis.

Conclusions:

• The developed strategy enables efficient formic acid synthesis through a coupled cathodic CO2 reduction and anodic methanol oxidation.
• The use of mSnO2/CC and CuONS/CF catalysts significantly improves electrocatalytic performance and reduces energy consumption.
• This approach offers a promising pathway for sustainable chemical production and carbon utilization.