Glycerol acetalization with formaldehyde using heteropolyacid salts supported on mesostructured silica

Abstract

In the present work, mesoporous silica supported heteropolyacid salts were studied systematically for glycerol acetalization with formaldehyde. Attention was focused on finding an appropriate loading of Cs2.5H0.5PW12O40 (Cs2.5) on mesoporous silica supports and studying the influence of the architecture of mesoporous silica on activity. Supported Cs2.5H0.5PW12O40 on 2D (SBA-15) and 3D (KIT-6 and SBA-16) pore lattice mesoporous silicas have been compared. The activity of all supported Cs2.5 catalysts was found superior to that of bulk Cs2.5 owing to the high surface area of the mesoporous supports. While the activity difference between 2D and 3D supports did not meet expectations, mesopore volume had a significant impact on activity, which is attributed to a good access to Cs2.5H0.5PW12O40 acid sites. The catalysts could be reused for three times (24 h each time), loosing only 10% glycerol conversion.