Dalian Institute of Chemical Technology realizes imaging of reaction and diffusion process in methanol-to-olefin molecular sieve catalyst

Recently, researcher Ye Mao, the team of Academician Liu Zhongmin, and the team of Professor Zhaochao Xu from the Fluorescence Imaging Research Group (Group 1818) of the National Engineering Laboratory of Methanol to Olefin, Dalian Institute of Chemical Technology, used multi-scale reaction-diffusion models and super-resolution structured illumination imaging. The combination of technology realizes the imaging of reaction and diffusion process in the crystal of SAPO-34 molecular sieve of methanol-to-olefin industrial grade, which can directly obtain the temporal and spatial distribution and evolution of guest molecules, carbon species and acidic sites during the reaction process.



Methanol-to-olefins has opened up the technical route for the production of low-carbon olefins from non-petroleum raw materials such as coal, natural gas and biomass, and has become an important production method for my country's ethylene and propylene and other bulk chemicals. The molecular sieve catalyst used in the methanol-to-olefin reaction has a unique pore structure that limits molecular mass transfer, which enables it to achieve higher selectivity for low-carbon olefins and accelerate the deactivation of the catalyst by carbon deposition. Therefore, obtaining the non-uniform distribution of reactants and products in the molecular sieve crystals due to mass transfer limitation in time and space is of great significance for understanding the mechanism of catalyst carbon deposition deactivation. It is difficult to obtain the complete spatiotemporal evolution information of the reactant and product molecules, carbon species and acidic sites in the molecular sieve crystal at the same time with the commonly used spatio-temporal resolution spectral imaging technology.