Interaction between soot and stored NO_x during operation of LNT Pt-Ba/Al₂O₃ catalysts

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• 作者：Roberto Matarrese ; Nancy Artioli ; Lidia Castoldi ; Luca Lietti ; ^{luca.lietti@polimi.it} ; Pio Forzatti
• 关键词：Soot oxidation ; DPNR catalysts ; Simultaneous NOx and soot removal ; Diesel particulate NOx reduction ; NSR catalysts
• 刊名：Catalysis Today
• 出版年：2012
• 出版时间：30 April, 2012
• 年：2012
• 卷：184
• 期：1
• 页码：271-278
• 全文大小：737 K

文摘

The interaction of soot with nitrates stored on a model PtBa/Al₂O₃ LNT catalyst sample is here investigated under realistic conditions, i.e. upon lean/rich cycling in the presence of water and CO₂. The presence of soot inhibits the NO_x storage capacity of the catalyst during the lean phase at different temperatures, in the range 200-350 ¡ãC, but does not affect significantly the regeneration process of the stored nitrates. Simultaneously with the NO_x storage, soot is converted to CO₂ at temperatures above 300 ¡ãC. Soot is oxidized by NO₂ formed by NO oxidation on Pt sites, but the participation of the stored nitrates in the soot oxidation is also likely, as pointed out by TPD/TPO experiments showing the occurrence of a surface reaction involving soot and the stored nitrates.