S. Storck et al., AMORPHOUS SN SI MIXED OXIDES, MILD SOLID LEWIS-ACID CATALYSTS FOR ESTERIFICATION AND ETHERIFICATION REACTIONS/, Journal of catalysis, 172(2), 1997, pp. 414-426
Novel amorphous porous mixed oxides of Sn, Si, and Al were prepared by
the sol-gel process for use as solid acid catalysts. The materials we
re characterized by XRD, HRTEM, SEM, EDX, argon-physisorption, DRIFTS,
and pyridine adsorption followed by FTIR. The catalysts show very few
Bronsted sites and some Lewis acid sites. The pore architecture of th
e materials was studied by the hydrocracking test of decane which indi
cated weak activity but clear shape selectivity for most of the mixed
oxides. Further catalytic testing included the direct esterification r
eaction of pentaerythritol with stearic acid to pentaerythritoltetrast
earate and the etherification of 1-hexanol and 1-naphthol with isobute
ne. The esterification reaction was studied under reaction conditions
close to industrial ones. The catalysts were found to be as active as
commercial homogeneous and heterogeneous catalysts. While the activity
found in the esterification reaction can be correlated with the incre
ase in surface area and the decrease in Sn content, no correlation wit
h microstructural parameters was found in the etherification reactions
. (C) 1997 Academic Press.