|作者：||N. Gunasekaran, S. Rajadurai, J. J. Carberry|
1Laboratory of Catalysis, Department of Chemical Engineering, University of Notre Dame
2Cummins Engine Co., Inc.
|刊名：||Catalysis Letters, 1995, Vol.35 (3-4), pp.373-382|
|关键词：||solid oxide solutions; perovskite type oxides; supported noble metals; nitrous oxide decomposition;|
|英文摘要：||Abstract(#br)The catalytic decomposition of nitrous oxide to nitrogen and oxygen has been investigated over various solid oxide solutions (SOS), La 0.8 Sr 0.2 MO 3−δ (M=Cr, Fe, Mn, Co or Y), La 1.8 Sr 0.2 CuO 4−δ and supported Pd, Pt catalysts. The reaction was carried out in a gradientless recycle reactor at 1 atm pressure with a feed gas containing about 0.5% N 2 O (in helium). Among the various solid solutions, La 0.8 Sr 0.2 CoO 3−δ showed a maximum N 2 O conversion of 90% at 600‡C. The order of activity observed for N 2 O decomposition was La 0.8 Sr 0.2 CoO 3−δ >La 0.8 Sr 0.2 FeO 3−δ >La 1.8 Sr 0.2 CuO 4−δ > La 0.8 Sr 0.2 MnO 3−δ La 0.8 Sr 0.2 CrO 3−δ ≈La 0.8 Sr 0.2 YO 3−δ . The activity of La 0.8 Sr 0.2 CoO 3−δ was compared with supported Pd, Pt and also with unsubstituted LaCoO 3... catalysts under similar reaction conditions. Among all the catalysts tested in this study, Pd/Al 2 O 3 showed the lowest light-off temperature for N 2 O decomposition. The activity of La 0.8 Sr 0.2 CoO 3−δ was found to be comparable to Pd/Al 2 O 3 catalyst at temperatures above 500‡ C. The influence of added oxygen (about 4%) in the feed was examined over La 0.8 Sr 0.2 CoO 3−δ and Pd/Al 2 O 3 catalysts and only in the case of cobalt catalyst was the conversion of N 2 O decreased by ∼13%. By choosing varied sintering conditions, La 0.8 Sr 0.2 CoO 3−δ of different BET surface areas were prepared and the light-off temperature was found to decrease with increase in surface area. The results obtained over solid solutions are discussed on the basis of the cation mixed valency and oxygen properties of the catalyst.|