Introduction by James Castle, SSS Editor

In the late 1950’s, as part of my PhD studies I had a need to remove ppm traces of hydrocarbons from otherwise pure oxygen (I had discovered that they influenced the oxidation of magnesium). As a result I came to appreciate the efficacy of the Arneil catalyst (copper oxide on Kieselguhr) for this purpose.   Now, in the volume of SSS that is just going to print we have a fine set of spectra from a modern version of this class of catalysts in which CuO and other oxides are distributed within a perovskite structure.  CuO/La0.6Sr0.4Co0.2Fe0.8O3-Powder by XPS, Marta Maria Natile, Alessandro Galenda, Fabio Poletto, and Antonella Glisenti, SSS, Vol 15,
This is one of three articles in volume 15 from the group at the Università di Padova, Italy, which deal with the distribution of metals oxides on porous supports to yield enhanced catalytic activity.

CuO/La0.6Sr0.4Co0.2Fe0.8O3-Powder by XPS

Marta Maria Natile, Alessandro Galenda, Fabio Poletto, and Antonella Glisenti

Surf. Sci. Spectra 15, 14 (2008);
doi:10.1116/11.20070802

A CuO/La0.6Sr0.4Co0.2Fe0.8O3-_ supported system was obtained by depositing, by wet impregnation, 10 wt% CuO loading on the La0.6Sr0.4Co0.2Fe0.8O3-_ surface. The surface properties are investigated by means of XPS. Besides the wide scan spectrum, detailed spectra for the La 3d, Sr 3d, Co 2p, Fe 2p, Cu 2p, O 1s, and C 1s regions, and related data, are presented and discussed.

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From La2O3 To LaCoO3: XPS Analysis

Marta Maria Natile, Alessandro Galenda, and Antonella Glisenti

Surf. Sci. Spectra 15, 1 (2008);
doi:10.1116/11.20061006

Nanostructured LaCoO3 powder was prepared by a new approach: cobalt oxide nanoparticles were deposited, by wet impregnation, on the La2O3 surface. The La2O3 support was prepared by precipitation from a basic solution of La_NO3_3•6H2O. The precipitate was dried at 353 K for 2 h and calcined at 923 K for 6 h in air. Nanostructured LaCoO3 was obtained by wet impregnation of La2O3 with aqueous solutions of Co_NO3_2•6H2O: _Co/La_nomimal _ 1.0 _nominal atomic ratio is obtained from the precursors weighed quantities_. The obtained suspension was maintained under stirring for two days and then kept in rest for one day. Water was evaporated in air and the obtained solid was dried at 353 K for 2 h and at 923 K for 6 h in air. The thermal treatment in air promotes a solid state reaction between La-O and Co-O and then the formation of LaCoO3.
 

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Perovskite-type oxides, ABO3, are known to be very good oxidation catalysts. The redox properties of the B cation, the availability of weakly bonded oxygen at the surface and the presence of lattice defects have been often claimed as responsible for their catalytic activity. Moreover, their performances can be improved if they are nanodimensioned. The present study focuses on the development of new LaCoO3-based catalysts for alcohol _such as methanol, ethanol_ steam reforming. Several La0.6Sr0.4Co1-yFeyO3-_ _y_0.2, 0.5, 0.8_ were prepared by the citrate gel method and calcined at 1073 K for 5 h in air. Herein, the influence of the cobalt/iron ratio on the surface properties was investigated.

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