Journal article
The effect of the Rh–Al, Pt–Al and Pt–Rh–Al surface alloys on NO conversion to N2 on alumina supported Rh, Pt and Pt–Rh catalysts
Department of Chemistry, Jagiellonian University, 30-060 Kraków, Ingardena 3, Poland1
Laboratoire de Réactivité de Surface, Université P. et M. Curie, 4 Place Jussieu, 75 252 Paris Cedex 05, France2
Fritz Haber Institut der Max Planck Gesellschaft, Faradayweg 4-6, D-14195 Berlin, Germany3
Regional Laboratory of Physicochemical Analyses and Structural Research, 30-060 Kraków, Ingardena 3, Poland4
NO conversion to N2 in the presence of methane and oxygen over 0.03at.%Rh/Al2O3, 0.51at.%Pt/Al2O3 and 0.34at.%Pt–0.03at.%Rh/Al2O3 catalysts was investigated.δ-Alumina and precious metal–aluminum alloy phases were revealed by XRD and HRTEM in the catalysts.The results of the catalytic activity investigations, with temperature-programmed as well as steady-state methods, showed that NO decomposition occurs at a reasonable rate on the alloy surfaces at temperatures up to 623K whereas some CH4 deNOx takes place on δ-alumina above this temperature.
A mechanism for the NO decomposition is proposed herein. It is based on NO adsorption on the precious metal atoms followed by the transfer of electrons from alloy to antibonding π orbitals of NO(ads.) molecules. The CH4 deNOx was shown to occur according to an earlier proposed mechanism, via methane oxidation by NO2(ads.) to oxygenates and then NO reduction by oxygenates to N2.
| Language: | English |
|---|---|
| Publisher: | Elsevier BV |
| Year: | 2007 |
| Pages: | 187-193 |
| ISSN: | 18734308 and 09205861 |
| Types: | Journal article |
| DOI: | 10.1016/j.cattod.2006.08.009 |
