| Abstract |
The study of partial oxidation of methane (POM) over bimetallic nickel- or copper-actinide oxides was undertaken. Binary intermetallic compounds of the type AnNi(2) (An = Th, U) and ThCu2 were used as precursors and the products (2NiO UO3, 2NiO ThO2 and 2CuO ThO2) characterized by means of Xray diffraction, X-ray photoelectron spectroscopy, Raman spectroscopy and temperature-programmed reduction. The catalysts were active and selective for the conversion of methane to H-2 and CO and stable for a period of time of approximate to 18 h on stream. The nickel catalysts were more active and selective than the copper catalyst and, under the same conditions, show a catalytic behaviour comparable to that of a platinum commercial catalyst, 5 wt\% Pt/Al2O3 The catalytic activity increases when uranium replaces thorium and the selectivity of this type of materials is clearly different from that of single metal oxides and/or mechanical mixtures. The good catalytic behaviour of the bimetallic copper- and nickel-actinide oxides was attributed to an unusual interaction between copper or nickel oxide and the actinide oxide phase as showed by H-2-TPR, XPS and Raman analysis of the catalysts before and after reaction. (C) 2010 Elsevier B V. All rights reserved. |
