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RESEARCH PRODUCT

Pumice-Supported Nickel Catalysts

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description

A series of nickel catalysts supported on pumice was prepared by precipitation and impregnation techniques. The influence of the calcination and reduction temperatures on the structural properties such as lattice parameters and particle dimensions of the oxide precursors and of the reduced catalysts was investigated by X-ray diffraction measurements. The effect of structural changes on the catalytic activity in the hydrogenation of carbon monoxide has been evaluated. The turnover frequencies, as well as product distributions, are discussed in terms of the influence of the support properties and of its interaction with the metal. Changes of the C2+yield over CH4yield ratio versus nickel dispersion are attributed to the presence of the alkali ions in the support structure. The catalytic performance of the catalysts does not change after 15–18 h time on stream. Indeed, the X-ray diffraction and photoelectron spectroscopy analysis of the catalysts, before and after reaction, excluded sintering of the metal particle, as well as coke formation.