Mesoporous (Ta, Nb)3W7 Modified with Stearic Acid Used as Solid Acids for Esterification

Mesoporous solid acids Ta 3 W 7 and Nb 3 W 7 were prepared from TaCl 5 and NbCl 5 with WCl 6 in the presence of stearic acid (SA) via a sol-gel method, respectively. For comparison, mesoporous Ta 3 W 7 -P123 mixed oxides and mesoporous Nb 3 W 7 -P123 mixed oxides were synthesized in the same way. The catalysts were characterized through TGA, XRD, SEM, TEM, BET, and NH 3 -TPD. Experimental results showed that Ta 3 W 7 -SA and Nb 3 W 7 -SA exhibited several advantages such as higher activity, shorter preparation period, lower cost, stronger acid sites, and higher surface area, which had potential to be used as mesoporous heterogeneous catalysts in biodiesel production.