INFRARED MICROSCOPIC STUDY OF SORPTION AND DIFFUSION OF TOLUENE IN ZSM-5

Time-resolved FTIR microscopy was used to investigate in situ the tran sport and sorption of toluene in individual ZSM-5 crystals with varyin g degree of perfection. The results indicate that the rate of transpor t of toluene in the pore system of zeolite ZSM-5 strongly depends upon the degree of crystal intergrowth. The diffusion coefficients observe d with single crystals were 3 orders of magnitude higher than the diff usion coefficients measured for a polycrystalline sample. The first re sults of this new method to study diffusion in microporous materials a re compared to the results from other techniques.