Alkylation of Phenol with tert-Butanol Catalyzed by Mesoporous Material with Enhanced Acidity Synthesized from Zeolite MCM-22 Ke Song Æ Jingqi Guan Æ Shujie Wu Æ Ying Yang Æ Bo Liu Æ Qiubin Kan Received: 16 June 2008 / Accepted: 19 August 2008 / Published online: 17 September 2008 Ó Springer Science+Business Media, LLC 2008 Abstract Using zeolite MCM-22 as source and cetyltri- methylammonium bromide (CTAB) as template, mesoporous material denoted as M-MCM-22 with enhanced acidity has been synthesized and characterized by XPD, FT-IR, N 2 adsorption–desorption, 27 Al-MAS NMR, IR spectra of pyridine adsorption, and NH 3 -TPD techniques, etc. The catalytic performance of M-MCM-22 was tested in alkylation of phenol with tert-butanol, indicating that M-MCM-22 showed highly and steadily catalytic proper- ties. The highest conversion of phenol could be achieved at 418 K, while the highest selectivity to 2, 4-di-TBP was obtained at 398 K. It is found that high temperature is advantageous to form 4-TBP, whereas low weight hourly space velocity (WHSV/h -1 ) is helpful for both conversion of phenol and selectivity to 2,4-DTBP. It is also shown that high ratio of tert-butanol/phenol is beneficial for obtaining high conversion of phenol and selectivity to 2,4-di-TBP. Keywords Mesoporous Á MCM-22 Á Enhanced acidity Á Butylation Á Phenol 1 Introduction Butylation of phenol with tert-butanol is a typical Friedel– Crafts alkylation reaction catalyzed by acid. Catalysts for this reaction include Lewis acids [1] (such as AlCl 3 and BF 3 ), Brønsted acids [2] (such as H 3 PO 4 ,H 2 SO 4 , HF, HClO 4 ), cation exchange resins [3], metal oxides [4], zeolite [5–9] and mesoporous aluminosilicate materials [10–17], etc. Based on the intensity of acidity, the distri- bution of products is different. Weak acid catalysts mainly lead to an etherified product such as phenyl ether, t-BPE. Moderate acid catalysts give the product of p-tert-butyl phenol. If strong acid catalysts are used in the alkylation reaction, 2, 4-di-tert butyl phenol is a dominant product. Based on the kinetics, o-tert-butyl phenol is the jarless product of alkylation of phenol with tert-butanol. However, due to steric hindrance, o-tert-butyl phenol is isomerized into p-tert-butyl phenol readily. Both p-tert-butyl phenol and 2, 4-di-tert-butyl phenol are the important feedstock for antioxidants, ultraviolet absorbers and heat stabilizers for polymeric materials in industry [18, 19]. Alkylation of phenol with tert-butanol is an important way to producing the two products. Molecule sieve catalysts have been widely used in the alkylation reaction because of their inherent advantages: uniform pore size, high thermal stability, environmental friendliness, etc [20]. For the alkylation of phenol with tert-butanol over zeolite cata- lysts, both conversion of phenol and selectivity to products are varied according to different structure and character of zeolites. Among zeolite catalysts, zeolite beta and Y show considerably catalytic properties. However, the pore sizes of these zeolites are too small to form 2, 4-di-TBP and 2, 4, 6-tri-TBP. Although mesoporous materials such as Al-MCM-41, Al-MCM-48, Al-SBA-15 and Al-TUD are used in the alkylation reaction [10–17], the conversion of phenol is lower than that achieved over zeolite beta and zeolite Y, and the selectivity to 2, 4-di-TBP is also low. It is well known that the pore walls of conventional meso- porous materials are amorphous, leading to weak acidity and limitation of use in the alkylation reaction. Therefore, new materials which combine the large pore sizes of mesoporous materials with the strong acidity of micropo- rous zeolites become very attractive. K. Song Á J. Guan Á S. Wu Á Y. Yang Á B. Liu Á Q. Kan (&) College of Chemistry, Jilin University, Changchun 130023, People’s Republic of China e-mail: qkan@mail.jlu.edu.cn 123 Catal Lett (2008) 126:333–340 DOI 10.1007/s10562-008-9626-y