Decomposition of N2O over Hexaaluminate Catalysts

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• 作者：Marta Santiago ; Javier P&eacute ; rez-Ramí ; rez
• 刊名：Environmental Science & Technology
• 出版年：2007
• 出版时间：March 1, 2007
• 年：2007
• 卷：41
• 期：5
• 页码：1704 - 1709
• 全文大小：433K
• 年卷期：v.41,no.5(March 1, 2007)
• ISSN：1520-5851

文摘

Catalytic N₂O decomposition has been studied overmetal-substituted hexaaluminates with the general formulaABAl₁₁O₁₉, where A = La, Ba, and B = Mn, Fe, Ni. Thematerials were prepared by coprecipitation via the carbonateroute followed by calcination at 1473 K for 10 h. Inductivelycoupled plasma optical emission spectroscopy (ICP-OES), X-ray diffraction (XRD), transmission electronmicroscopy (TEM), and N₂ adsorption techniques wereused to characterize the catalysts. The activity in direct N₂Odecomposition was evaluated by means of temperature-programmed reaction and steady-state experiments. Fe- andMn-containing hexaaluminates present the highestactivities. The Ni-containing catalysts are significantlyless active, comparable to the hexaaluminates without metalsubstitution. The catalytic activity was practically notinfluenced by the A cation (La or Ba) in the structure. TheFe- and Mn-substituted hexaaluminates exhibit highactivity and stability for N₂O decomposition in mixturessimulating the outlet of the Pt-Rh gauzes in ammonia oxidationreactors, containing N₂O, NO, O₂, and H₂O. These materialsare promising for high-temperature abatement of thispowerful greenhouse gas in the chemical industry, particularlyin nitric acid and caprolactam production.