Catalysis Today, Vol.107-08, 942-948, 2005
Nopol synthesis over Sn-MCM-41 and Sn-kenyaite catalysts
Several methods were used to prepare Sn loaded kenyaite and MCM-41 silicates: ion exchange, incipient wetness impregnation and chemical vapor deposition. Catalysts were evaluated for nopol synthesis by the Prins condensation of beta-pinene and paraformaldehyde. The resulting catalysts were characterized by elemental analysis, TGA, XRD, FTIR, BET surface area and UV-vis. Kenyaite samples modified with Sn by ion exchange were more resistant to leaching than those modified by chemical vapor deposition (CVD), while Sn-MCM-41 samples prepared by CVD were more active, selective to nopol and resistant to leaching than Sn-MCM-41 prepared by impregnation. In general, Sn-MCM-41 catalysts even at low Sn loadings exhibited higher nopol yields than Sn-kenyaite. (c) 2005 Elsevier B.V. All rights reserved.