Taking carbon dioxide from the atmosphere has often been proposed as a solid strategy for reducing its levels, and now a new method might make it easier and potentially more lucrative.
A team from the University of South California has shown for the first time that carbon dioxide can be directly converted into methanol simply by using a catalyst. Although methanol is not currently a widespread fuel, if it was available readily and cheaply it could be used as an alternative to gasoline.
The planet naturally recycles carbon between animals, plants, the ocean, and the atmosphere, but by burning fossil fuels we are freeing more CO2 than Earth can take in. Carbon Capture techniques aim to remove or, at least, recycle the carbon already present in the air.
The production of carbon neutral fuels has recently become a very important issue in chemical research, and the conversion of carbon dioxide into methanol is definitely important. The chemical industry requires more than 63.5 million tonnes (70 million tons) of methanol annually to make plastic, as well as other compounds.
"Direct CO2 capture and conversion to methanol using molecular hydrogen in the same pot was never achieved before. We have now done it!" G. K. Surya Prakash, senior author of the research, told Phys.org. Their findings are published in the Journal of the American Chemical Society.
The team was able to achieve this feat using a homogenous ruthenium-based catalyst that can convert CO2 with a moderately high yield: 79 percent of the carbon dioxide is converted into methanol.
The catalyst is both versatile and robust. It can produce methanol even at low CO2 concentrations and it was used for over five runs without significant loss of activity. The only downside at the moment is that the catalyst needs to be kept at a temperature between 125 to 165 °C (257 to 329 °F), and high temperature severely reduces the lifetime of catalysts.
"We will continue the studies to develop more robust catalysts that work around 100 to 120 °C," Prakash said. "We would like to perform the chemistry in a preparatively useful way, wherein there are no solvent or reagent losses."