Studies on SO2 Tolerance and Regeneration over Perovskite-Type LaCo1鈥?i>xPtxO3 in NOx Storage and Reduction

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• 作者：Xiuyun Wang ; Xinxin Qi ; Zhilin Chen ; Lilong Jiang ; Ruihu Wang ; Kemei Wei
• 刊名：Journal of Physical Chemistry C
• 出版年：2014
• 出版时间：June 26, 2014
• 年：2014
• 卷：118
• 期：25
• 页码：13743-13751
• 全文大小：494K
• ISSN：1932-7455

文摘

A series of perovskite-type LaCo_1鈥?i>xPt_xO₃ (x = 0, 0.05, 0.08, and 0.10) were synthesized by the sol鈥揼el method and well characterized by XRD, N₂ physisorption, H₂-TPR, TEM, and XPS. NO_x storage and reduction (NSR) performances of LaCo_1鈥?i>xPt_xO₃ were initially evaluated using NO-to-NO₂ conversion, NO_x storage capacity, and NO_x conversion. The results demonstrate that NSR performances of Pt-substituted perovskites are higher than that of LaCoO₃, and LaCo_0.92Pt_0.08O₃ possesses the best NSR properties with NO_x conversion of ca. 90% at 350 掳C. Moreover, LaCo_0.92Pt_0.08O₃ exhibits higher resistance to SO₂ poisoning and better regenerability than 1 wt % Pt/16 wt % Ba/Al₂O₃ in NSR. No obvious deactivation is observed after LaCo_0.92Pt_0.08O₃ has been treated at 850 掳C for 40 h and subjected to NO_x reduction at 350 掳C for 200 h; the perovskite structure is well maintained in the process. The addition of 10 vol % H₂O lowers NO_x conversion to about 77%, but the removal of water from the reaction gas immediately raises NO_x conversion to 90%.