In Situ XRD Investigation of Ni_0.9M_0.1O (M = Co, Ce, Mn, Zr) Nickel-Based Catalists Activation Process

Abstract

In this work the activation process and the effect of modifying additives on the phase composition and structure of a series of catalysts with the general composition Ni0.9M0.1O (M = Co, Ce, Mn, Zr) synthesized by co-precipitation were studied. The influence of the additives on the initial state of the samples was investigated by XRD, and their influence on the NiO reduction process was studied by in situ XRD and TPR-H2. It was shown that the introduced modifiers influence on the structure and microstructure of the initial samples, increasing the value of the specific surface and decreasing the average size of NiO CSR. Introduction of Mn, Co leads to formation with NiO oxide of solid solutions of replacement. For Ce and Zr the release of CeO2 oxide and X-Ray-amorphous ZrOx is observed. The use of these additives leads to an increase in the temperature of NiO reduction to the metallic state compared to the massive oxide. In addition, the effect of modifying additives on the particle size of the final metal is observed. The introduction of Ce and Mn decreases the average size of the NiO CSR in 2–5 times compared to the massive NiO.