The effect of UTL layer connectivity in isoreticular zeolites on the catalytic performance in toluene alkylation

• Published in: Catalysis today 2016-11, Vol.277, p.55-60
• Main Authors: Žilková, Naděžda, Eliášová, Pavla, Al-Khattaf, Sulaiman, Morris, Russell E., Mazur, Michal, Čejka, Jiří
• Format: Article
• Language: English
• Subjects: ADOR zeolites; IPC zeolites; OKO; PCR; Toluene alkylation; UTL
• ISSN: 0920-5861; 1873-4308
• DOI: 10.1016/j.cattod.2015.09.033

•Series of zeolites with the UTL layers but different connectivity is prepared.•All zeolites are deeply characterized.•Toluene alkylation with isopropyl alcohol depends on the channel accessibility.•Rate of consecutive reactions depends on the level of toluene conversion.•n-Propyl toluenes are formed with lower extent due to the absence of intersecting 10-ring channels. Toluene alkylation with isopropyl alcohol was used as a model reaction to investigate the effect of UTL-type layer connectivity in a series of isoreticular zeolites and related zeolitic materials. All prepared catalysts possess the same structure of the layers but their connectivity differs from amorphous pillars (IPC-1PI), double-four-rings (UTL), single-four-rings (IPC-2=OKO, International Zeolite Association code), oxygen bridges (IPC-4=PCR), or their combinations (IPC-6 and IPC-7). X-ray powder diffraction, scanning electron microscopy, and nitrogen adsorption isotherms were employed to characterize structural and textural properties of the studied catalysts. Deuterated acetonitrile was adsorbed on catalysts to determine the concentrations and type of individual acid sites. Toluene alkylation with isopropyl alcohol evidenced that toluene conversion increases with increasing size of zeolite channels. Simultaneously, selectivity in cymenes increased as open structure of these catalysts did not present optimum reaction volume for the bimolecular reaction of cymenes with toluene to n-propylbenzenes.