22 February 2018
A versatile carbon-based catalyst
Published online 28 May 2017
Carbon catalyst reduces CO2 emissions while making fuel.
The catalysts currently used to reduce carbon dioxide are both expensive and unstable; they’re also hard to produce. However, scientists from Saudi Arabia and Canada used a simple and scalable technique to make this catalyst1.
They modified multiwalled carbon nanotubes by adding a porous carbon membrane. The catalyst ended up with a porous structure, containing nanopores, micropores and macropores. The macropores provide mass transport highways while the nanopores and micropores make up a large surface area.
“It is possible to tune the shape and size of the catalyst which is immune to oxidation and poisoning by impurities in electrochemical reactions,” says lead author Hong Wang from the University of Toronto, Canada.
The porous structure allows for a three-phase contact between the catalyst, aqueous electrolyte and gaseous carbon dioxide. The catalyst also exhibits high electrical conductivity, and aids reduction of carbon dioxide in aqueous solution. It showed no decay in activity even after being used for 36 hours.
The current efficiency of formate production is as high as 81%.
Converting CO2 into formic acid electrochemically has several environmentally-friendly applications, as per the researchers, including de-icing runways and planes at airports, and manufacturing fuel cells for robots and drones.
- Wang, H. et al. Efficient electrocatalytic reduction of CO2 by nitrogen-doped nanoporous carbon/carbon nanotube membranes – a step towards the electrochemical CO2 refinery. Angew. Chem. Int. Ed. http://dx.doi.org/10.1002/anie.201703720 (2017)