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Abstract: Liquid phase di-tert-butylperoxide synthesis from the condensation reaction between tert-butyl alcohol and tert-butylhydroperoxide over microporous H-beta zeolites, having Si/Al molar ratios ranging from 11.5 to 120, has been investigated. With increasing Al content or in other words the acidity of H-beta zeolite, the catalytic activity is increased and passes through maxima; however, the selectivity for di-tert-butylperoxide is decreased initially to a small extent and then maintain almost the same level. Among the different Al-containing beta zeolites, the catalyst with a Si/Al molar ratio of 40 shows the best performance in the above condensation reaction. Additionally, when compared with other commonly used heterogeneous acidic microporous zeolites (H-ZSM-5, H-mordenite, H-Y, H-MCM-22) and mesoporous solids (Al–MCM-41, Al:SBA-15) having similar Si/Al ratios but different pore structures, the catalytic activity of the H-beta zeolite in the di-tert-butylperoxide synthesis process is found to be much higher. [Copyright &y& Elsevier]

Liquid-phase bisphenol F synthesis from phenol and formaldehyde condensation reaction in the presence of water has been investigated over mesoporous Al:MCM-41 catalysts, with different Si/Al ratios, prepared by a post-synthesis grafting method. The catalysts have been characterized for their phase purity, surface area, average pore diameter and acidity. Introduction of Al into the framework of MCM-41 increased the acidity; however, the increase in the acidity only up to a certain level increased the acid-catalyzed phenol and formaldehyde condensation activity. Among the different Al-grafted MCM-41 molecular sieves (having Si/Al ratios from 15 to 200 mol mol-1), Al:MCM-41 having a Si/Al ratio of 70 mol mol-1 shows the best catalytic performance in the bisphenol F synthesis process. [Copyright &y& Elsevier]

Mesoporous aluminosilicate molecular sieves, Al-containing MCM-41, with different Si/Al ratios were synthesized by four different methods: sol–gel, hydrothermal, template cation exchange and grafting. The catalysts prepared by sol–gel, grafting and template cation exchange methods are effective for the incorporation of large amounts of aluminum into the framework of MCM-41. The catalytic activities of the resulting Al-containing MCM-41 samples were tested in the cracking of cumene and the dehydration of 2-propanol, as model acid-catalyzed reactions, and then compared with the results obtained from microporous H-ZSM-5 and HY zeolites. The Al-containing MCM-41 catalysts prepared by different methods behaved differently in acting as acidic catalysts; the catalyst (having almost same Si/Al ratio) prepared by sol–gel method showed higher cracking activity, whereas that prepared by template cation exchange method showed higher dehydration activity. Moreover, these Al-containing MCM-41 catalysts are more catalytically active than microporous HY zeolite for cumene cracking and 2-propanol dehydration reactions. [Copyright &y& Elsevier]