Missouri researchers lead work on electrocatalysis of CO2 to produce hyper efficient electro-biodiesel

In Missouri, researchers at Washington University in St. Louis, the University of Missouri, and their collaborators at Texas A&M University have used electrocatalysis of carbon dioxide to create an electro-biodiesel that is 45 times more efficient and uses 45 times less land than soybean-based biodiesel production. Results of their work are published online in Joule Oct. 31, 2024.

The team used electrocatalysis, a type of chemical reaction initiated by electron transfers to and from reactants on surfaces of catalysts, to convert carbon dioxide into biocompatible intermediates, such as acetate and ethanol. The intermediates were then converted by microbes into lipids, or fatty acids, and ultimately became biodiesel feedstock.

To prompt the electrocatalysis, the team designed a new zinc- and copper-based catalyst that produces diatomic carbon intermediates that could be converted into lipids with an engineered strain of the Rhodococcus jostiii (RHA1) bacterium, known to produce high lipid content. This strain also boosted the metabolic potential of ethanol, which could help to prompt conversion of acetate, an intermediate, to the fatty acid.

After developing the novel process, the team analyzed the impact of the process on climate change and found encouraging results. By using renewable resources for the electrocatalysis, the electro-biodiesel process could reduce 1.57 grams of carbon dioxide per gram of electro-biodiesel produced with the by-products of biomass, ethylene and others, giving it the potential for negative emissions. In contrast, conventional diesel production from petroleum produces 0.52 grams of carbon dioxide per gram, and biodiesel production methods produce 2.5 grams to 9.9 grams of carbon dioxide per gram of lipids produced.