MAO Zhihong, WANG Jie, LI Guixian, WANG Xiaorui, WANG Chengjun

(College of Petrochemical Technology, Lanzhou University of Technology, Lanzhou 730050, China)

Abstract: The surface of acid-activated palygorskite (Pa) was modified by grafting 3-aminopropyl-triethoxysilane (the silylated Pa denoted Pa_APTES) for immobileizetion of molybdovanadophosphoric heteropoly acids (H₅PMo₁₀V₂O4₀,). The samples were characterized by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), Brunauer–Emmett–Teller (BET) specific area measurement.The catalytic activity was tested for the acetal of benzaldehyde with ethylene glycol, under the optimal conditions, i.e., 115 ℃ as reaction temperature, ethylene glycol:acetophenone=1.75:1 and 0.1g of H₅PMo₁₀V₂O₄₀/Pa_APTES catalyst, 8 mL of cyclohexane as the water-carrying agents, 95.49% conversion of benzaldehyde and 99.22% selectivity for benzaldehyde cylic ethylic acetal were achieved within 120min. The recycling tests show that the catalyst can be easily separated from the reaction system.

Key words: heteropoly acid; silanized palygorskite; acetal; catalysis

E-mail: lgxgd@lut.cn 

Journal of Molecular Catalysis, Vol. 25, Issue 5, 2011, 393-399