Characterization of CuO species in CuO/CeO2-Al2O3, catalysts by in-situ XRD, Raman spectroscopy and TPR

CuO species and thermal solid-solid interaction in CuO(w,%)/CeO2-Al2O3 catalysts prepared by an impregnation method are characterized by in-situ XRD, Raman spectroscopy and H-2-TPR techniques. Experiment results show that CuO presents as highly dispersed and bulk CuO on the surface of CuO(33.3%)/CeO2-Al2O3 calcined at 300 degrees C. At high temperatures CuO can be transferred from the surface into the internal layer of CeO2 and the transference of CuO increases with increasing the calcination temperature. Some of CuO that exists in the internal layer of CeO2 presents as bulk CuO, some of that interacts with the support Al2O3 to produce CuAl2O4. The calcination temperature also promotes the CuO-Al2O3 interaction. It shows that the existence of different CuO species can be effectively confirmed by in-situ XRD, Raman spectroscopy and H-2-TPR techniques.