Metal-carrier interface regulates the mechanism of CO dissociation in Fischer-Tropsch synthesis

【 Instrument R&D of Instrumentation Network 】Recently, Huang Yanqiang, a researcher of the Catalysis and New Materials Laboratory of the Dalian Institute of Chemical Physics, Chinese Academy of Sciences, and Zhang Tao, a member of the Chinese Academy of Sciences, have made progress in regulating the mechanism of CO dissociation in the Fischer-Tropsch synthesis reaction. The TiOx coating layer formed on the intermediate Ru nanoparticles (NPs) can directly participate in the dissociation of the CO bond, thereby significantly improving its activity in the Fischer-Tropsch synthesis reaction.

The Fischer-Tropsch synthesis reaction can convert non-petroleum resources (coal, natural gas, biomass, etc.) into high-value-added fuels or chemicals through synthesis gas, providing a technical route for the development of alternative energy sources. In the Fischer-Tropsch synthesis reaction, the steps of CO dissociation and further hydrogenation to form CHx intermediate species are crucial, usually occurring on the surface of Fe, Co, Ru metals, where the metal Ru exhibits excellent reaction performance. However, Ru-based catalysts have a significant particle size effect, and Ru NPs around 8 nm have higher Fischer-Tropsch reactivity, which severely reduces the utilization efficiency of the precious metal Ru. The development of highly dispersed and highly active Ru-based Fischer-Tropsch synthesis catalyst is of great significance.

The team used the characteristics of rutile RuO2 and TiO2 to have the same crystal form and high lattice matching, and successfully synthesized a highly dispersed and highly stable Ru/TiO2 catalyst, in which the particle size of Ru NPs was only about 2 nm, which was reduced at a high temperature of 600 ℃ No significant change in particle size after treatment. The team achieved a controlled adjustment of the degree of strong metal-support interaction by changing the reduction temperature of the catalyst, and obtained Ru/TiO2 catalysts with different metal-support interface structures. Studies have shown that under the synergy of the appropriate metal-support interface, Ru NPs of about 2 nm can exhibit excellent Fischer-Tropsch reactivity under mild conditions (160 ℃), and their TOF value is the highest reported in the literature. Through various characterization techniques and combined with theoretical calculations, it was found that the TiOx coating formed by the strong metal-support interaction can directly participate in the dissociation of CO bonds, thereby significantly improving the Fischer-Tropsch reactivity of Ru-based catalysts. This work not only reveals the catalytic mechanism of the strong metal-support interaction in the Fischer-Tropsch synthesis reaction, but also provides new ideas for the design of other highly dispersed metal catalysts.

The research results were published in "Nature Communications" (Nature Communications). This work was supported by the National Key R&D Program "Nano Science and Technology" key special project, the National Outstanding Youth Science Foundation project, the Chinese Academy of Sciences’ strategic pilot technology project "Precision Construction Principles and Measurements of Functional Nanosystems" and so on.