A novel approach to direct electrocatalytic reduction of carbon dioxide could help in fight against global warming

The technique uses a rhenium-based catalyst capable of targeting CO2 molecules with high selectivity even in very low concentration

Scientists at Tokyo Institute of Technology, Japan, have devised a new technique for direct electrocatalytic reduction of carbon dioxide (CO2). The technique uses a rhenium-based catalyst capable of targeting CO2 molecules with high selectivity even when CO2 concentration is as low as one per cent.

Scientists hope their novel approach to target CO2 molecules could one day enable direct utilisation of CO2 emitted into the atmosphere by heavy industries, thereby helping in the fight against global warming.

Electrocatalytic reduction of CO2 refers to a chemical process in which CO2 molecules are converted into carbon monoxide (CO). A major drawback of almost all methods proposed so far for electrocatalytic reduction of CO2 is that they target pure CO2 - whereas the emissions from power plants and industry contain just 3-13 per cent CO2. Another disadvantage of these methods is their large energy consumption.

The current study was led by Osamu Ishitani of the Department of Chemistry at Tokyo Institute of Technology (Tokyo Tech), in association with Tetsuya Nishikawa, Hiromu Kumagai, and other colleagues.

The team demonstrated the ability of a rhenium-based catalyst to reduce low-concentration CO2 to CO with high selectivity (94 per cent) in the presence of a chemical called triethanolamine. Researchers think a likely reason behind efficient performance of rhenium-based catalyst is the efficient insertion of CO2 molecule into the rhenium-oxygen bond.

"If we can develop the technology which we reported in this paper, we will possibly be able to use CO2 from the air to obtain artificial petroleum - similar to natural photosynthesis in future - by combining this technology with solar cells," said Dr. Osamu Ishitani.

The researchers now aim to continue investigating potential techniques to help reduce real-world CO2 levels.

The current study was supported by Core Research for Evolutional Science and Technology (CREST) programme on Molecular Technology.

The findings of the study are published in journal Chemical Science.