Fischer-Tropsch (FT) synthesis is a catalytic reaction that synthesizes petroleum alternative fuels and chemicals such as light oil from syngas (a mixed gas of carbon monoxide and hydrogen).Syngas can be easily produced from natural gas (including shale gas and methane hydrate), biomass, coal, and combustible waste, so the FT synthesis reaction can be said to be one of the catalytic reactions that has a large industrial impact.However, cobalt is an important metal with a small amount of resources, and the price soaring with the advent of electric vehicles requires a significant reduction in the amount of cobalt used.

　The conventional FT synthesis catalyst has a structure in which cobalt nanoparticles are immobilized on the surface of the catalyst carrier.Large cobalt nanoparticles synthesize long-molecular-weight gas oil and jet fuel, and small cobalt nanoparticles synthesize short-molecular-weight LPG and light olefins.

　On the other hand, this research group has developed a cobalt-based capsule catalyst covered with a silica layer, which overturns the conventional theory that "the size of cobalt particles determines the length of the molecule of the product".The new catalyst has newly discovered that small cobalt nanoparticles synthesize long-molecular-weight gas oil and jet fuel, and large cobalt nanoparticles synthesize short-molecular-weight LPG and light olefins.

　With this discovery, the cobalt content, which was 30-40% by weight in the conventional supported FT commercial catalyst, can be reduced to 5-10% or less.The research group aims to put this catalyst into practical use as a new commercial catalyst for FT synthesis plants, and also aims to apply it to the synthesis of liquid fuels from carbon dioxide and hydrogen, which is a reaction similar to FT synthesis.

Paper information:[Nature Communications] Confined Small-sized Cobalt Catalysts Stimulate Carbon-Chain Growth Reversely by Modifying ASF Law of Fischer-Tropsch Synthesis