Synthesis of MgO and MgO–CeO2 by co-precipitation for the catalytic conversion of acetone by aldol condensation

Abstract

This study deals with the synthesis of catalytic samples containing MgO and 10, 15 and 25 wt% of CeO2 by co-precipitation method for aldol condensation of acetone. The obtained powders were characterized by X-ray diffraction (XRD), Raman spectroscopy, temperature programmed desorption of CO2, X-ray photoelectron spectroscopy, nitrogen physisorption, and atomic force microscopy. The materials exhibited XRD patterns corresponding with cubic MgO and fluorite phase of ceria, medium and weak strength basic sites, characteristic electronic properties and distinctive trends regarding textural properties. The aldol condensation of acetone was carried out using the prepared catalyst samples; a decrease in acetone conversion as function of time-on-stream was noted for all catalyst, being the best performance exhibited by the sample containing 10 wt% ceria. The selectivity toward the different products of aldol condensation of acetone was dependent on catalytic sample, which was related to the unique properties of those solids. Diacetone alcohol was best produced by MgO-25 wt% ceria; for mesityl oxide yield, an increase in selectivity as time-on-stream was observed being the best material the sample MgO-10wt% ceria; whereas for phorone, the profiles indicate almost yield reduction as time-on-stream function, indicating the best performance the sample containing 15 wt% of CeO2. Isophorone was optimally produced by using pure MgO which was attributed to the presence of medium strength basic sites and adequate textural properties.