Refined application of the m-xylene isomerization to the characterization of shape-selective zeolite properties
1989; Elsevier BV; Volume: 9; Issue: 3 Linguagem: Inglês
10.1016/0144-2449(89)90032-8
ISSN1873-3115
AutoresM. Richter, Wolfgang Fiebig, H.‐G. JERSCHKEWITZ, G. Lischke, G. Öhlmann,
Tópico(s)Catalysis and Oxidation Reactions
ResumoThe usefulness of m-xylene isomerization for characterizing shape-selective zeolite properties via the p-xylene/o-xylene ratio is examined. It is shown that for a correct determination the prevailing conversion/selectivity relationship has to be taken into account. The concept of initial selectivities is applied for separating contributions of this relationship from those actually associated with a modification of shape-selective catalyst properties. Examples are given for a ZSM-5-type zeolite (shape selective), a H-mordenite (non-shape selective), and γ-Al2O3 as reference. The influence of dealumination and extraction of nonframework Al species and of the binder has been studied for the ZSM-5-type catalyst along with mechanistic aspects (influence of reaction temperature, influence of m-xylene concentration, and mass transfer effects).
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