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[Display omitted] • Quantitatively control surface barriers via modifying ZSM-5 zeolite surface. • A higher reaction rate achieved with the increase of surface permeability. • Spatiotemporally visualize evolution of guest molecules in zeolite crystals. • Enhance zeolite accessibility to increase reaction rate by lowering surface barriers. Mass transfer of guest molecules is crucial for zeolite catalysis. Compared to intracrystalline diffusion, the surface barriers in zeolite catalysis have been less understood. Taking furfuryl alcohol oligomerization catalyzed by ZSM-5 zeolites as model reaction, here we present a single-crystal level study and gain insight into the surface barriers induced spatiotemporal evolution of oligomer products using structured illumination microscopy (SIM). It is shown that, as a result of the enhanced accessibility to zeolite crystals, promoting the surface permeability leads to the increase in catalytic reaction rate that is characterized as the generation rate of oligomer products. [ABSTRACT FROM AUTHOR]

• A reaction-diffusion model based on the dual-cycle reaction mechanism and Maxwell-Stefan diffusion theory is developed. • Effect of coke deposition on diffusion and adsorption isotherm is taken into account. • The model is validated against experiments of MTO reaction over SAPO-34 zeolites with different crystal size. • How diffusion affects catalyst lifetime and product selectivity in MTO reaction can be modeled. In this work, a modeling approach based on the dual-cycle mechanism and Maxwell-Stefan diffusion theory is developed to investigate the reaction and diffusion in methanol-to-olefins (MTO) process over SAPO-34 zeolites. In this work, the effect of coke formation on diffusion and adsorption in SAPO-34 zeolites were taken into consideration. The diffusivities and adsorption isotherms of the molecules of reactant and main product were derived by experimental measurements of the uptake rate of guest molecules. This model was used to study MTO reaction over SAPO-34 zeolites with different crystal size. It is shown that the model can capture the main features of MTO reaction as obtained by experiments, for instance, the different roles of the olefins-base cycle and aromatic-base cycle at different stage of the reaction. This model can predict the evolution of activated coke and non-activated coke during the reaction process. In particular, the simulation results directly show that the formation of non-activated coke can cause the pore blocking inside SAPO-34 zeolites and constrain the diffusion of different guest molecules to various extend. This is essential for us to understand the effect diffusion on catalyst lifetime and product selectivity in MTO reaction over SAPO-34 zeolites. [ABSTRACT FROM AUTHOR]