Jump to main content
Jump to site search

Issue 3, 2001
Previous Article Next Article

Spinel-type oxide catalysts for low temperatureCO oxidation generated by use of an ultrasonic aerosol pyrolysis process

Author affiliations

Abstract

The aim of this study was to generate spinel-type oxides by a continuous ultrasonic aerosol pyrolysis procedure and to evaluate the chemical and physical properties of the product powders. The ultrasonic aerosol pyrolysis process consists of three steps, which include “atomisation” of an aqeous metal nitrate solution, transport to the furnace system and controlled thermal decomposition of the precursor aerosol. The synthesis method allows the production of pure CuMn2O4, LiMn2O4 and CuCo2O4 spinels, whereas NiMn2 − xO4 contains small quanitities of α-Mn2O3. The powders are finely dispersed, mesoporous products exhibiting a uniform morphology. Scanning electron microscopy reveals that the product is made up of hollow spheres. XRD, TA and XPS results reveal that CuMn2O4 exists in a metastable state. It segregates in air already at temperatures of 300 °C, whereas in an inert atmosphere the spinel is stable up to 600 °C. XPS measurements indicate the presence of a redox system in the form of Image ID:b007306g-t1.gif, which is one of the main features for the high turnover rates of CO with O2 of this catalyst already at room temperature. XPS measurements, after treatment of CuMn2O4 with CO and O2, confirm the highly reactive surface. NiMn2O4 and CuCo2O4 also show high activities in the catalytic CO oxidation. LiMn2O4 is rather inactive. A comparison of CuMn2O4 with LiMn2O4 points to the crucial influence of the copper cations on the conversion rates of the CO oxidation. In the synthesis of CuMn2O4 the introduction of glucose into the starting metal nitrate solution revealed changed properties of the product powders: as a consequence, the distribution of the cations on the surface is changed and markedly smaller conversion rates for the catalytic CO oxidation are observed.

Back to tab navigation
Please wait while Download options loads

Publication details

The article was received on 08 Sep 2000, accepted on 04 Dec 2000 and first published on 01 Feb 2001


Article type: Paper
DOI: 10.1039/B007306G
Citation: J. Mater. Chem., 2001,11, 905-911
  •   Request permissions

    Spinel-type oxide catalysts for low temperature CO oxidation generated by use of an ultrasonic aerosol pyrolysis process

    G. Fortunato, H. R. Oswald and A. Reller, J. Mater. Chem., 2001, 11, 905
    DOI: 10.1039/B007306G

Search articles by author