Study of restricted diffusion in porous catalysts by NMR

Journal Article · Sun Apr 01 04:00:00 EDT 1990 · A.I.Ch.E. Journal (American Institute of Chemical Engineers); (USA)

DOI:https://doi.org/10.1002/aic.690360407· OSTI ID:6716700

Cheng, W C; Luthra, N P; Pereira, C J ^[1]

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1. Grace (W.R.) and Co., Columbia, MD (USA). Research Div.

The diffusion of 1,3,5 tri-tert-butylbenzene (TTB) into cylindrical {gamma}-alumina extrudates of varying micropore diameter and macropore volume has been studied by NMR spectroscopy. The proton NMR signal of the methyl proton of TTB in the micropores of the alumina extrudate was found to be well resolved and shifted upfield relative to that in the bulk liquid by 0.55 ppm. The area under the shifted peak is proportional to the liquid concentration of TTB in the micropores. The change in the intensity of this peak as a function of time and measurements of the amount of TTB absorbed on the surface alumina at equilibrium were used to calculate the effective diffusivity of TTB in each extrudate. Measured values of the effective diffusivity are in reasonable agreement with predictions using correlations in the literature. These observations suggest a new method for measuring the liquid-phase effective diffusivity in porous materials.

• OSTI ID: 6716700
• Journal Information: A.I.Ch.E. Journal (American Institute of Chemical Engineers); (USA), Journal Name: A.I.Ch.E. Journal (American Institute of Chemical Engineers); (USA) Vol. 36:4; ISSN AICEA; ISSN 0001-1541
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400102 -- Chemical & Spectral Procedures
400201* -- Chemical & Physicochemical Properties
ALUMINIUM COMPOUNDS
ALUMINIUM OXIDES
AROMATICS
BENZENE
CATALYSTS
CATALYTIC EFFECTS
CHALCOGENIDES
DIFFUSION
FLUIDS
HYDROCARBONS
LIQUIDS
MATERIALS
NMR SPECTRA
ORGANIC COMPOUNDS
OXIDES
OXYGEN COMPOUNDS
PHASE STUDIES
POROUS MATERIALS
SPECTRA