【Frontiers in HaiChuan Chemical Technology】Dalian Institute of Chemical Physics uncovers the molecular mechanism by which the flexible molecular sieve CoS-1 efficiently catalyzes propane dehydrogenation

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The molecular mechanism by which the flexible molecular sieve CoS-1 facilitates the efficient catalysis of propane dehydrogenation, as revealed by our research team: Published on April 22, 2025. Recently, the Research Group on Computational and Data-Driven Catalysis (Group 511) led by Researcher Xiao Jianping from our National Key Laboratory of Energy Catalytic Conversion has, in collaboration with Researcher Wang Liang and Professor Xiao Fengshou from Zhejiang University, as well as Professor Liu Xi from Ningxia University, made new progress in the field of propane dehydrogenation for the production of propylene. They developed a cobalt silicate zeolite catalyst (CoS-1) that features a unique molecular sieve framework capable of stabilizing isolated tetrahedral cobalt sites; this catalyst exhibits excellent catalytic performance, enabling a propylene yield of 9.7 kgC3 per kgcat–1 h–1. Furthermore, under industrial conditions, its propane dehydrogenation performance is superior to that of conventional industrial PtSn/Al2O3 catalysts. Low-carbon olefins are important raw materials for the modern chemical industry. Direct production of low-carbon olefins from shale gas through the dehydrogenation of low-carbon alkanes holds significant research value. In the preliminary work, Xiao Jianping’s team collaborated with the experimental group to systematically study, through theoretical calculations, the alkane dehydrogenation properties of various isolated metal sites that stabilize silicalic molecular sieve frameworks, achieving a series of research results (J. Am. Chem. Soc., 2020) ； J. Am. Chem. Soc., 2022 ； Chem, 2023). In this work, Xiao Jianping’s team revealed the structure of the active center in the CoS-1 catalyst and the chemical reasons for its high performance through stability studies and catalytic dynamic simulations. Studies have found that the isolated Co sites stabilized by the molecular sieve framework exhibit a (Si−O)δ−Coδ+−(OH−Si)4−δ coordination structure during the reaction process. The entropy effect associated with their flexible framework can significantly reduce the propane dehydrogenation barrier at high temperatures, enabling the CoS-1 catalyst to have a lower energy barrier compared to the Pt3Sn alloy. Furthermore, the team calculated the alkane dehydrogenation rates on these two catalysts using microkinetic simulations and found that although CoS-1 has a lower energy barrier, the process of propane diffusing into the pores of the molecular sieve results in significant entropy loss, causing the propane concentration near the Coδ+ sites to be much lower than that on the Pt3Sn surface. As a result, the overall reaction rate of CoS-1 is slightly lower than that of Pt3Sn at the initial stage of the reaction. Furthermore, the team proposed that the non-covalent adsorption property of molecular sieves facilitates the rapid desorption of the product propylene, reducing the rate of catalyst carbon deposition and thereby enabling CoS-1 to exhibit superior long-term stability. A related study titled “Cobaltosilicate zeolite beyond platinum catalysts for propane dehydrogenation” was recently published in Nature Catalysis. The co-first authors of this work are Associate Researcher Zhou Hang from Zhejiang University and Li Huan, a doctoral student in Group 511 of our institute. The above work was supported by projects such as the **Key Research and Development Program** and the National Natural Science Foundation.