Synthesis and characterization of S2O82 −/ZnFexAl2 − xO4 solid acid catalysts for the esterification of acetic acid with n-butanol

Abstract New spinel-types of S 2 O 8 2 − /ZnFe x Al 2 −  x O 4 solid acid catalysts were prepared by sol–gel method. Their catalytic performances for the synthesis of n -butyl acetate were investigated. The catalysts were characterized by means of XRD, IR, XPS, FT-IR of adsorbed pyridine and NH 3 -TPD. The experimental results showed that S 2 O 8 2 − /ZnFe x Al 2 −  x O 4 solid acid catalysts maintained the spinel structure as well as the support of ZnFe x Al 2 −  x O 4 . Fe 3 + ions were well incorporated and highly dispersed into the spinel lattice. S 2 O 8 2 − /ZnFe 0.15 Al 1.85 O 4 exhibited the maximum conversion of acetic acid with 98.2%. Moreover, S 2 O 8 2 − /ZnFe 0.15 Al 1.85 O 4 showed better reusability, which remained above 72.7% conversion of acetic acid even after being used five times.