{'fraction_non_alphanumeric': 0.027298850574712645, 'fraction_numerical': 0.011494252873563218, 'mean_word_length': 5.394495412844036, 'pattern_counts': {'":': 0, '<': 1, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
PFG NMR measurements of tortuosity factors for diffusion in meso- and macropores of FCC catalysts

Pulsed field gradient (PFG) NMR is applied to measure self-diffusion coefficients of 1,3,5 triisopropyl-benzene in the particles of several industrial FCC catalysts having different systems of mesoand macropores. Relating these diffusivities to the self-diffusion coefficient of 1,3,5 tri-isopropyl-benzene in the liquid phase, the tortuosity factors for diffusion in the mesoand macropores of the particles were obtained. The values of the tortuosity factors were found to increase with a increasing volumetric fraction of the small (< 20 nm) mesoand macropores in the total intraparticle volume.