Acetalization of glycerol with acetone over Co[II](Co[III]xAl2-x)O4 derived from layered double hydroxide

The rapid rising production of biodiesel has led to a drastic surplus of glycerol, and catalytic conversion of glycerol into value-added products is of great importance. Among of which, solketal, derived from the acetalization of glycerol and acetone, is an important chemical and fuel additive. In this work, a series of solid acid Co[II](Co[III](x)Al2-x)O-4 catalysts were prepared via controlled decomposition of layered double hydroxide and used in the acetalization of glycerol with acetone. It was found that Co[II](Co[III](x)Al2-x))O-4 is highly active and selective for this reaction under mild condition. The selectivity of solketal reached 98.6% with a 69.2% conversion of glycerol at 130 degrees C and 3.0 h over Co[II](Co[III](1.25)Al-0.75)O-4. Characterizations results indicated that the performance of Co[II](Co[III](x)Al2-x))O-4 depended mainly on the acidity of Co[II](Co[III](x)Al2-x)O-4, and the conversion of glycerol increased with the amount of strong acid sites.