Innovative catalyst converts CO2 to methane using electricity

Innovative catalyst converts CO2 to methane using electricity
by Robert Schreiber
Berlin, Germany (SPX) Oct 04, 2024

Researchers from the University of Bonn and University of Montreal have developed a highly efficient catalyst capable of converting carbon dioxide (CO2) and water (H2O) into methane (CH4) using electricity. This new method holds potential for producing methane, the primary component of natural gas, in a climate-neutral way if powered by green electricity. Methane can be used for heating or as a chemical industry feedstock. Additionally, this system could be adapted to create other vital chemical compounds, making it valuable for broader industrial applications. The results of the study were published in 'Nature Chemistry'.

Professor Nikolay Kornienko, who conducted the research at the University of Bonn after moving from the University of Montreal, explained that methane production presents challenges due to the need to react a gas with a liquid. "We used electricity as the driving force instead," explains Kornienko. "By using climate friendly electricity, we can produce, for example, methane that doesn't contribute to global warming."

A gas diffusion electrode was used to bring carbon dioxide and water together. During the reaction, oxygen atoms are removed from CO2 and replaced with hydrogen atoms sourced from water, resulting in methane. However, the process risks side reactions, such as water splitting into hydrogen and oxygen. As Kornienko's assistant, Morgan McKee, emphasized, "We have to prevent the water coming into contact with the electrode" to ensure efficient methane production.

The catalyst plays a critical role by accelerating the CO2 reaction. It features an "active center" that weakens the bond between the carbon and oxygen atoms in CO2, enabling the replacement with hydrogen atoms while minimizing unwanted reactions. Hydrophobic molecular side chains keep water at bay while transporting hydrogen atoms to the active center for reaction with carbon.

With over 80 percent efficiency and minimal side products, this catalyst shows promise. However, it is not yet suitable for large-scale methane production. Kornienko suggested that the method could be applied to other catalysts for large-scale applications, particularly for producing chemical compounds like ethylene, a key material in plastic production.

Research Report:Hydrophobic molecular assembly at the gas-liquid-solid interface drives highly selective CO2 electromethanation