Electrocatalytic methane conversion via in-situ generated superoxide radicals in an aprotic ionic liquid

Area of Science:

• Electrochemistry
• Catalysis
• Sustainable Chemistry

Background:

• Direct conversion of methane (CH4) to valuable chemicals is crucial for sustainable energy.
• Electrochemical activation and partial oxidation offer a decentralized approach.
• Developing efficient catalysts and reaction conditions remains a challenge.

Purpose of the Study:

• To develop an electrochemical system for room-temperature conversion of methane to methanol and ethanol.
• To investigate the role of V3O7·H2O as an anodic catalyst and ionic liquid as an electrolyte.
• To elucidate the reaction mechanism involving superoxide radicals.

Main Methods:

• Electrochemical synthesis in a non-diaphragm bath.
• Utilizing V3O7·H2O as the anodic catalyst.
• Employing [BMIM]BF4 ionic liquid as the supporting electrolyte.
• Molecular dynamics (MD) and Density Functional Theory (DFT) simulations.

Main Results:

• Methanol (CH3OH) and ethanol (CH3CH2OH) were successfully produced.
• Achieved a superior methanol Faraday efficiency (FE) of 32.2% and selectivity of 76.8%.
• MD simulations showed enhanced mass transfer due to CH4-[BMIM]BF4 interactions.
• DFT calculations indicated V sites in V3O7·H2O facilitate CH4 adsorption and dissociation.

Conclusions:

• The developed electrochemical system enables efficient room-temperature conversion of methane.
• Superoxide radicals (O2-) play a key role in the formation of methanol and ethanol.
• The combination of V3O7·H2O catalyst and [BMIM]BF4 electrolyte is effective for methane electrooxidation.