Researchers in China report development of a stable catalyst for direct production of gasoline-range hydrocarbons from carbon dioxide hydrogenation.

Converting this greenhouse gas into value-added liquid fuels can contribute to mitigating CO2 emissions and reduce dependence on petrochemicals. However, CO2 is a fully oxidized, thermodynamically stable and chemically inert molecule, characteristics that pose challenges for its activation and hydrogenation to hydrocarbons. Relevant research to date has focused on selective hydrogenation of CO2 to short-chain products, with little emphasis on long-chain, gasoline-range (C5–C11) hydrocarbons.CO2 hydrogenation to gasoline-range hydrocarbons over Na–Fe3O4/zeolite multifunctional catalyst. Image credit: WEI JianCO2 hydrogenation to gasoline-range hydrocarbons over Na–Fe3O4/zeolite multifunctional catalyst. Image credit: WEI Jian

Following the premise that the key to this process is a highly efficient catalyst, researchers from the Dalian Institute of Chemical Physics of the Chinese Academy of Sciences prepared a multifunctional Na–Fe3O4/HZSM-5 catalyst for the direct production of gasoline from CO2. The catalyst exhibited a remarkable stability for 1,000 h on-stream, as well as 78 percent selectivity to C5–C11 and low methane and carbon monoxide selectivity under industrial relevant conditions.

The gasoline fractions are mainly isoparaffins and aromatics. The catalyst structure enables reverse water-gas shift over three types of active sites: Fe3O4 sites, olefin synthesis over Fe5C2 sites, and oligomerization/aromatization/isomerization over zeolite acid sites. The concerted action of the active sites calls for precise control of their structures and proximity.