Aromatic Transformations Over Mesoporous ZSM-5: Advantages and Disadvantages

0437054 - ÚFCH JH 2015 RIV NL eng J - Journal Article
Musilová, Zuzana - Žilková, Naděžda - Park, S.-E. - Čejka, Jiří
Aromatic Transformations Over Mesoporous ZSM-5: Advantages and Disadvantages.
Topics in Catalysis. Roč. 53, 19-20 (2010), s. 1457-1469. ISSN 1022-5528. E-ISSN 1572-9028
Institutional research plan: CEZ:AV0Z40400503
Keywords : mesoporous ZSM-5 * alkylation * disproportionation
Subject RIV: CF - Physical ; Theoretical Chemistry
Impact factor: 2.359, year: 2010

Catalytic behavior of mesoporous ZSM-5 was investigated in toluene disproportionation, toluene alkylation with isopropyl alcohol, and p-xylene alkylation with isopropyl alcohol to understand the effect of the presence of mesopores. Three ZSM-5 zeolites (conventional one and two mesoporous differing in the mesopore volume) having similar Si/Al ratio were synthesized and characterized as for their acidity (internal and external) as well as their micropore/mesopore volume. No substantial differences among three samples were observed as for the type and concentration of Bronsted and Lewis acid sites as well as their location in zeolite channels or on external surface of zeolite crystals. Conversions of toluene and p-xylene increased with increasing volume of mesopores in ZSM-5 zeolite while the selectivity to individual products depended on the type of reaction. In general, selectivity to sum of xylenes in toluene disproportionation, sum of isopropyltoluenes in toluene alkylation and to 1-isopropyl-2,5-dimethylbenzene in p-xylene alkylation increased due to a shorter contact time molecules spent in mesoporous ZSM-5 catalysts. In contrast, para-selectivity decreased as diffusion pathways were shorten due to the presence of mesopores.
Permanent Link: http://hdl.handle.net/11104/0240636