Today, planes pump a large amount of carbon dioxide into the atmosphere that heats the climate. But someday, carbon dioxide aspirated from the atmosphere could be used to power aircraft.
A new iron-based catalyst converts carbon dioxide into fuel for aircraft, researchers reported online on Dec. 22 in Nature Communications. Unlike cars, airplanes cannot carry batteries large enough to run on wind or solar electricity. But if CO2, instead of oil, were used to make aircraft fuel, that could reduce the carbon footprint of the air travel industry, which currently accounts for 12 percent of all transport-related CO2 emissions.
Past attempts to convert carbon dioxide into fuel have depended on catalysts made of relatively expensive materials, such as cobalt, and have required multiple stages of chemical processing. The new catalyst powder is made from cheap ingredients, including iron, and transforms CO2 in a single step.
When placed in a reaction chamber with carbon dioxide and hydrogen gas, the catalyst helps the carbon in the CO2 molecules to separate from oxygen and bind to hydrogen, forming the hydrocarbon molecules that make up the reaction fuel. Oxygen atoms left over from CO2 combine with other hydrogen atoms to form water.
Tiancun Xiao, a chemist at Oxford University, and colleagues tested their new carbon dioxide catalyst in a small reaction chamber set at 300 ° C and pressurized to about 10 times the air pressure at sea level. For 20 hours, the catalyst converted 38 percent of the chamber’s carbon dioxide into new chemicals. About 48 percent of those products were aircraft fuel hydrocarbons. Other by-products included similar petrochemicals, such as ethylene and propylene, that can be used to make plastics.