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Chemical Research in Chinese Universities ›› 2006, Vol. 22 ›› Issue (4): 533-536.

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Vapour-phase O-methylation of Catechol with Methanol on Ti-containing Phosphate Catalysts

ZHU Xiao-mei1, LI Xue-mei2, LIU Gang1, ZOU Xiu-jing1, WANG Yan-li1, JIA Ming-jun1, ZHANG Wen-xiang1   

  1. 1. College of Chemistry, Jilin University, Changchun 130021, P. R. China;
    2. Shanghai Huayi Acrylic Acid Co. Ltd., Shanghai 200137, P. R. China
  • Received:2005-07-28 Online:2006-08-24 Published:2011-08-06
  • Supported by:

    Supported by the Development Project of Science and Technology of Jilin Province(Nos. 20050309-1 and 20040563), the Specialized Research Fund for the Doctoral Program of Higher Education(No.20040183003), CNPC(No.JTGS 20040010), and the National Natural Science Foundation of China(No.20403006).

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Abstract: Ti-containing phosphate(Ti-P-O) catalysts with different molar ratios of P to Ti(0-2.0) were synthesized and characterized by XRD, N2-adsorption/desorption, IR and temperature-programmed desorption(TPD) methods. The catalytic properties of Ti-P-O samples in the vapor-phase O-methylation of catechol with methanol were also studied. The catechol conversion increases with the increase of the molar ratio of P to Ti in a range of 0-0.33, while a further increase in the P content leads to a decrease of the catalytic activity. Meanwhile, the selectivities of the catalysts to the main product(guaiacol) increase gradually with the increase of the molar ratio of P to Ti. The presence of relatively strong Lewis acidic and/or basic sites in the P-free catalyst should be responsible for the formation of C-alkylation products. The weak acid-base characteristics of the catalysts are favourable for the mono-O-methylation of catechol. In comparison with the Lewis acidic sites, the Br(o)nsted acidic sites on the catalysts are more active for the title reaction.

Key words: Phosphates, Acid-base catalysis, Guaiacol, Catechol, O-Methylation