Enhanced accessibility and utilization efficiency of acid sites in hierarchical MFI zeolite catalyst for effective diffusivity improvement

The determination of utilization degree and effective diffusivity is very important to the design of a new hierarchical zeolite catalyst. By employing Thiele modulus analysis in the cumene cracking reaction, it is found the effective diffusion length in hierarchical MFI zeolite was obviously shortened. The enhanced adsorption capacity and accelerated diffusion rate of cumene molecules in hierarchical MFI zeolite remarkably promoted accessibility to the internal surface and obviously improved the utilization of acid sites.