Research papers published in the Journal of the American Chemical Society and Angewandte Chemie, a team of Stanford researchers claim that is possible to convert carbon dioxide into ethanol with very few by-products.
The researchers honed in on ethanol because it is useful for the fuel, polymers and pharmaceutical industries. It is also commonly used in the agricultural sector for crop growth.
“If we are able to turn CO2 into valuable chemicals, we close the cycle,” said the lead author of the two papers, Chengshuang Zhou, recent PhD graduate in chemical engineering. “We have the opportunity of not producing more carbon, but instead circulating the carbon that is already out there.”
The researchers needed to combine carbon dioxide with hydrogen, but this can not be done without the creation of a catalyst first.
Using nanoscale design and synthesis, the researchers created a ruthenium-indium oxide (Ru/In2O3) catalyst and put it to the test. In a stainless steel tube, the team flowed carbon dioxide and hydrogen across a small scoop of the powdered catalyst, adding pressure and heat to speed the reaction, and analysed the gases that came out the other end.
After several attempts, they found that the input gases converted to 70% ethanol and only carbon monoxide as a by-product. The team believe this process could be scaled to settings such as industrial chimneys.
By demonstrating the potential to produce a high rate of ethanol, Zhou claims the work sets the stage for future efforts to use metals that are more abundant.
The team plans to develop a catalyst that can be widely used in conjunction with various sources of carbon dioxide – including captured from the air or from a smokestack – to turn the gas into ethanol, which can then be bottled and sold.
