Scientists identify new approach for converting carbon dioxide to methane

Scientists have identified a new approach for converting carbon dioxide to methane in one step in a single pot called 'one-pot catalysis system' thus eliminating an intermediate step usually needed in the reduction process.

The new approach utilises a series of catalytic reactions to electrochemically reduce carbon dioxide to methane, the main ingredient in natural gas.

The study was published in the journal 'Nature Communications'.

"We want to supply renewable electricity and take carbon dioxide from the atmosphere and convert it to something else in one step. This is a key contribution to this vision," said Bingjun Xu, author of the study.

To convert carbon dioxide into valuable fuels, you have to start with a surface made of copper. Copper can be used to reduce carbon dioxide into carbon monoxide, which can then be further transformed into substances such as methane. This process is relatively simple, but it requires two reactors and costly separation and purification steps.

The research team used computations and experiments to design a one-pot catalysis system. Add carbon dioxide, and a series of chemical reactions will happen without the need to stop and add more chemicals.

To do this, the team added special nanostructure silver surfaces, to the copper surfaces. The silver portion attracts carbon monoxide molecules, which then migrate to the copper portion and reduce to methane. The system yields a higher concentration of methane than copper-only systems.

"In this work, the primary novelty is to combine these two in a configuration so that several steps of reaction could occur in one system," said Xu.

"We systematically modified the composition, the silver-to-copper ratio in the structure. Those are key to the selectivity and ability to combine the reactions.