De-NOx process in the presence of CO on perovskites La-Ni-O supported on AI2O3 and ZrO2

✍ Scribed by A. Ladavos; P.J. Pomonls

• Publisher: Elsevier Science
• Year: 1993
• Tongue: English
• Weight: 523 KB
• Volume: 17
• Category: Article
• ISSN: 0920-5861
• DOI: 10.1016/0920-5861(93)80022-s

✦ Synopsis

The reaction of NO dimlnation in the presence of equimofecuiar amount of CO was investigated on lanthanum nit&elate perovskiie species supported either on A1203 or ZrQ. The support was pretreated with ianthana whose presence was necessary for the devdopment of a LaNQ perovskite phase on alumina. On the contrary the phase developed on the zirconia based solids was La2NiO4. The solids based on alumina possess a spedfic surface area of 35. 65 m2g-l while those based on zirconia 3-7 mgg-1. The L;yNiOJZQ solids are more active for the NO elimination as compared to LaNiO$ A1203 ones, irrespectively if the activity is calculated per unit mass or unit area of the solids. The smaller activity of LaNQ/ Al$IIs is attributed to the stronger adsorption of NO on the Nf+s catalytic centers which result in an 25 36% excess conversion of NO as compared to CO. On the La$liO4/ ZQ sofiis the conversion of NO does not exceeds 12-14% that of CO, the excess of NO in both cases suffering disproportionation towards &O. The comparison between the behaviour of supported perovskltes on Zr& with that of the pure solids indicates that ZrQ acts most probably synergistically in boosting the activity of La2NiO4.