Design of highly efficient Zn-, Cu-, Ni- and Co-promoted M-AlPO4 solid acids: The acetalization of glycerol with acetone

Acetalization of glycerol with acetone was examined using M-AlPO4/xAlPO(4) (x=Zn, Cu, Ni, or Co) solid acid catalysts with enlarged surface areas. The relationship between the structural properties and the catalytic performances was investigated. The synthesized catalysts were systematically analyzed using various techniques, namely, XRD, SEM/TEM, EDX, BET surface area, pore size distribution, FTIR, UV-vis spectrophotometry and NH3-TPD. The XRD results suggested the formation of mesostructured amorphous materials. The SEM/TEM results showed that the materials had an ordered structure. All of the materials exhibited uniform pore size and high specific surface area. The strength of the acid sites of the M-AlPO4/xAlPO(4) (x=Zn, Cu, Ni, or Co) solid acid catalysts was studied by NH3-TPD. UV-vis spectrophotometry was used as a novel method to measure the exact amount of acid sites of the M-AlPO4/xAlPO(4) (x=Zn, Cu, Ni, or Co) solid acid catalysts. The resulting materials were found to exhibit excellent catalytic activity for the acetalization of glycerol with acetone. The reaction with M-NiAlPO4 showed the highest yield (75.44%) and the best selectivity (75.12%). (C) 2015 Elsevier B.V. All rights reserved.