Highly selective conversion of methanol to propylene: design of an MFI zeolite with selective-blockage of (010) surfaces

Abstract

As an important catalyst of methanol-to-propylene (MTP), ZSM-5 zeolite has an anisotropic diffusion path and large pore size, resulting in the formation of undesirable heavy aromatic by-products Herein, we developed a surface-specific silica deposition method to block straight channels of nanosized ZSM-5 crystals selectively. By such coating method, we can selectively suppress the yield of aromatics from the original 13% to 2.4% at 100% conversion of methanol. Trapped hydrocarbon pool species are directly confirmed by Aberration-Corrected S/TEM for the first time. Such a method of trapping and restricting hydrocarbon pool species in multiscale zeolite with 10-membered rings would significantly benefit its catalytic efficiency and olefin diffusion. Moreover, this is providing new methodologies for zeolite structure construction and will be greatly beneficial to industrial MTP process.