Preparation and physicochemical properties of individual and binary Ni and Ce oxides system

NiO, CeO2 and NiO/CeO2 catalysts were prepared using ceramic and wet impregnation routes followed by calcination at 400 °C, respectively. The crystalline phases produced due to the calcination at the mentioned temperature were characterized by XRD measurement. The microstructure, surface and catalytic properties of the calcined products of various solids were determined by transmission electron microscope, nitrogen adsorption at −196 °C and catalytic conversion of isopropanol at different temperatures.The results revealed that the crystallite sizes, specific surface areas and catalytic activity of individual oxides were greater than those of binary system. The binary oxides calcined at 400 °C constituted of well crystalline Ni and Ce oxides. A portion of NiO dissolved in CeO2 lattice in the binary oxides system by heating at 400 °C and the other portion remained as a separate phase. The dissolution process resulted in the formation of Ni–Ce–O compound with subsequent decrease in the degree of crystallinity of NiO and CeO2 phases. NiO and also CeO2 acted as dehydrogenation catalysts whereas its mixture acted as dehydrogenation and dehydration catalyst for isopropanol conversion. The activation energy of the catalytic reaction was determined for various investigated solids and was found to be dependent on the nature of the as-prepared system.

This paper aims to preparation and characterization of Ni/Ce mixed oxides with comparing these oxides with the individual oxides. From data analysis, we can prepare new nano-materials for the dehydrogenation and dehydration reactions to obtain acetone as important matter. It was found that Ni/Ce mixed oxides show an important activity and selectivity of acetone greater than that of propene. But the individual oxides led to formation of acetone only.Figure optionsDownload as PowerPoint slide