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

• Ceria doping with 10% Pr had a positive effect on RhOx-support interaction.
• The benefit on the catalytic activity was only obtained for water impregnation.
• Ethanol and acetone promoted Ce0.9Pr0.1O2 and RhOx sintering.
• The RhOx and Ce0.5Pr0.5O2 interaction was not as good as that with Ce0.9Pr0.1O2.

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 N2 adsorption at −196 °C, XRD, Raman spectroscopy, TEM, XPS and H2-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 RhOx 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 °C at 10 °C/min) because do not sinters during solvents combustion.

Figure optionsDownload high-quality image (145 K)Download as PowerPoint slide