Iron catalyst converts CO₂ to jet fuel

Peter P. Edwards predicts that future generations will look back at the way today’s scientists grappled with greenhouse gas problems and ask incredulously, “Bury CO₂ in the ground? Was that the best you could come up with?” His group at the University of Oxford thinks that converting the troublemaker gas to valuable compounds is a better way to go. To that end, Edwards, Benzhen Yao, Tiancun Xiao, and coworkers have come up with an inexpensive iron catalyst that converts carbon dioxide to jet fuel, a mixture of hydrocarbons in the C₈–C₁₆ range (Nat. Commun. 2020, DOI: 10.1038/s41467-020-20214-z). The team prepared a number of catalysts using a one-pot aqueous method in which they mixed iron nitrate and other starting materials with citric acid or other cation-complexing agents. Then they burned the resulting pastes in air, forming nanostructured catalysts, and used them to hydrogenate CO₂ to make jet fuel. Tests comparing the effects of adding various transition metals and alkali metals showed that doping the Fe-based compound with manganese and potassium improved its catalytic performance. Results show that under mild conditions, the unoptimized Fe-Mn-K catalyst converts roughly 40% of CO₂, producing C₈–C₁₆ hydrocarbons with nearly 50% selectivity and a mixture of light olefins, which are also industrially valuable.