Preparation of RhOx/CeyPr1-yO2 N2O decomposition catalysts by rhodium nitrate impregnation with different solvents

The effect of the solvent (water, ethanol or acetone) used to impregnate CeyPr1-yO2 (y =1, 0.9 or 0.5) supports with rhodium nitrate, in order to prepare N2O decomposition catalysts, has been studied. RhOx/CeyPr1-yO2 catalysts were prepared and characterized by N-2 adsorption at -196 degrees C, XRD, Raman spectroscopy, TEM, XP5 and H-2-TPR. The activity for N2O decomposition of the catalysts studied was related with the RhOx,-support interaction, and both the nature of the ceria support and of the solvent used for rhodium impregnation affected such interaction. Ceria doping with 10% praseodymium had a positive effect in the RhOx-support interaction, but the benefit on the catalytic activity was only obtained for water impregnation because the temperature peaks created during calcination of ethanol and acetone-impregnated catalysts promoted Ce0.9Pr0.1O2 and RhOx sintering. The interaction between RhO, and Ce0.5Pr0.5O2 was not as good as that with Ce0.9Pr0.1O2. The best catalyst was obtained by impregnating Ce0.9Pr0.1O2 with a water solution of rhodium. However, if acetone or ethanol must be used for any reason the pure ceria support is more suitable (under the calcination conditions of this study; 250 to 500 degrees C at 10 degrees C/min) because do not sinters during solvents combustion. (C) 2013 Elsevier B.V. All rights reserved.