Cracking of hydrocarbons on zeolite catalysts: density functional and Hartree-Fock calculations on the mechanisms of the Beta-scission reaction
Article Abstract:
The dynamics of the Beta-scission reaction in zeolites were investigated through quantum chemical calculations using density functional theory and Hartree-Fock methodologies. The reaction paths path RL, path HBCP and path HB were identified. It was determined that the transition states on all reaction paths signified complexes of the carbocation-like fragment with the negatively charged cluster. The fragments are not independent and interact vigorously with the negatively charged cluster by Coulomb attraction and hydrogen attraction.
Publication Name: Journal of Physical Chemistry B
Subject: Chemicals, plastics and rubber industries
ISSN: 1520-6106
Year: 1998
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Introduction of Zn, Ga, and Fe into HZSM-5 cavities by sublimation: identification of acid sites
Article Abstract:
A study was conducted to analyze the nature of zinc, gallium and iron after introduction into the zeolite by deposition from the vapor and on the induced acidity. Infrared spectroscopy and temperature-programmed reduction were used to carry out the analysis. Results indicated that upon the condensation of the vapor of a volatile precursor on the H-form of the zeolite, the concentration of Bronsted sites was lowered and a high level of ion exchange was then obtained.
Publication Name: Journal of Physical Chemistry B
Subject: Chemicals, plastics and rubber industries
ISSN: 1520-6106
Year: 1999
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Mass diffusion effect in large zeolite Y aggregates on Pd cluster size distribution: a combined in situ EXAFS/XRD study
Article Abstract:
The effect of reduction temperature and CO atmosphere on the size of Pd clusters inside the cavities of zeolite Y was investigated using a combination of EXAFS and X-ray diffraction. The macroscopic size and degree of compactness were found to have a great effect on the ultimate dispersion of Pd in the zeolite. Results also showed that the exposure of CO induces agglomeration of secondary Pd particles.
Publication Name: Journal of Physical Chemistry B
Subject: Chemicals, plastics and rubber industries
ISSN: 1520-6106
Year: 1998
User Contributions:
Comment about this article or add new information about this topic:
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