Reaction Kinetics and Catalysis Letters, Vol.70, No.2, 303-310, 2000
XRD and TPR studies of Cu-Al hydrotalcite derived highly dispersed mixed metal oxides
A series of Cu/Al catalysts, containing different proportions of copper and aluminium, have been prepared by coprecipitation using metal nitrate precursors and Na2CO3. The dried precipitate catalyst precursors were characterized by X-ray diffraction (XRD) to show the presence of Cu-Al binary hydrotalcite-like phase. The dried precipitates were calcined at 873 K for 3 h. The calcined catalysts were characterized by XRD and temperature-programmed reduction (TPR) methods to show the presence of unidentified mixed oxides. The results showed that the extent of metal-support interaction increased with copper loading due to the mixed oxides formed from the hydrotalcite-type phase during calcination. High dispersion of the mixed metal oxides was indicated by comparison with similar studies on Cu-Al catalysts, prepared by similar methods, whose precursors showed no hydrotalcite formation.
Keywords:hydrotalcite;Cu-Al mixed oxides;interdispersion;X-ray diffraction;temperature programmed reduction