Enhanced VOC oxidation over Ce/CoMgAl mixed oxides using a reconstruction method with EDTA precursors

CoMgAl hydrotalcites were synthesized as precursors of mixed oxides in order to obtain the oxidation catalysts of toluene. Additionally, mixed oxides were promoted with the incorporation of ceria which was carried out by two methods: the hydrotalcite reconstruction method using pre-synthesized cerium chelate as a precursor [Ce-EDTA]^-1; and by the traditional technique of wetness impregnation with Ce nitrate. The effect of the Ce element on the solid's physical properties and catalytic performance was investigated. The final oxides were analyzed using inductively coupled plasma-optical emission spectrometry (ICP), specific surface area, X-ray diffraction (XRD), temperature programmed reduction with H₂, (H₂-TPR), X-ray photoelectron spectroscopy (XPS) and catalytic tests. The Ce-CoMgAl catalyst synthesized by the reconstruction method provided a good toluene conversion. It is demonstrated that the incorporation of ceria and the activity on VOC oxidation were significantly influenced by the preparation method of the promoted catalyst, the use of EDTA providing better activity because the methodology improves the redox properties of the catalyst.