Effect of calcination temperature on the synthesis of Cu-Zn-Mg-Al quaternary oxides for the valorization of glycerol.

Abstract

OMM-Cu15Zn25-Tz mixed oxide catalysts were prepared by controlled thermal decomposition at different calcination temperatures from a layered double hydroxide (LDH) precursor. The mixed oxides were evaluated in the transesterification reaction between glycerol and dimethyl carbonate to obtain glycerol carbonate. LDH with M/Al ratio =3 (M = Cu + Zn + Mg) and a content of 15 at. % of Cu and 25% at. of Zn, with respect to M, was obtained by co-precipitation. The solids were characterized by XRD, MP-AES, EDS, N₂ adsorption-desorption, TPD-CO₂ and SEM. The influence of calcination temperature on the catalytic performance was investigated. Glycerol conversions of 95%, 96%, 90% and 48% were obtained in OMM-Cu15Zn25-T450, OMM-Cu15Zn25-T550, OMM-Cu15Zn25-T650 and OMM-Cu15Zn25-T750, respectively. The catalytic activities could be successfully correlated with the physicochemical properties of the materials.