Preparation and reaction mechanism of novel CeXCoyCuz oxide composite catalysts towards oxidation of o-xylene

CeXCoyCuz oxide composite catalysts were prepared by using polyethylene glycol, citrate sol-gel method combined with PMMA template for the oxidation of o-xylene. The catalysts were characterized by the X-ray diffraction (XRD), H2-temperature programmed reduction (H2-TPR), X-ray photoelectron spectros-copy (XPS) and Fourier transform infrared spectroscopy (FT-IR), etc. The catalytic activity for o-xylene was investigated. The catalytic degradation pathway and mechanism of o-xylene were inferred. The results show that CeO2 is mainly present on the surface of all catalysts. The surface area of Ce2Co1Cu1 is up to 77.2 m2/g, and the average pore size is 10.62 nm. It exhibits redox and sufficient Ce4+ and Ce3+, and reactive oxygen species, and has maximum O-H and C=O in the five catalyst samples. The catalytic activity of Ce2Co1Cu1 is the best at low temperature, with the T50 and T90 values of 235 and 258 degrees C at a space velocity of 32000 h-1, respectively. The o-xylene is oxidized to o-methyl benzaldehyde, and then further oxidized to o-methylbenzoic acid, and finally CO2 and H2O are formed.(c) 2021 Published by Elsevier B.V. on behalf of Chinese Society of Rare Earths.