Post-synthesis modification of TUN zeolite: Textural, acidic and catalytic properties

0359894 - ÚFCH JH 2012 RIV NL eng J - Journal Article
Kubů, Martin - Žilková, Naděžda - Čejka, Jiří
Post-synthesis modification of TUN zeolite: Textural, acidic and catalytic properties.
Catalysis Today. Roč. 168, č. 1 (2011), s. 63-70. ISSN 0920-5861. E-ISSN 1873-4308
R&D Projects: GA ČR GD203/08/H032; GA ČR GAP106/11/0819
Institutional research plan: CEZ:AV0Z40400503
Keywords : TUN * dealumination * desilication
Subject RIV: CF - Physical ; Theoretical Chemistry
Impact factor: 3.407, year: 2011

Dealumination, desilication and silylation of TUN zeolite was investigated and related to the catalytic behavior in toluene disproportionation and its alkylation with isopropyl alcohol. Only negligible concentration of acid sites was identified on the “external” surface of parent TUN zeolite and this concentration increased with increasing desilication. Silylation resulted in channel narrowing and probably some plugging. As a result, significant increase in the para-selectivity in toluene disproportionation and its alkylation with isopropyl alcohol was achieved. No changes in toluene conversion were observed for all parent and modified samples in toluene alkylation confirming diffusion and transport of products as the rate determining step in 10-ring zeolites. Selectivity to cymenes and p-cymene decreased with dealumination as well as desilication. In contrast, silylation increased both cymene (80%) and p-cymene (90%) selectivity in toluene alkylation.
Permanent Link: http://hdl.handle.net/11104/0197587