The influence of nonstoichiometry on LaMnO3 perovskite for catalytic NO oxidation

被引：215

作者：

Chen, Jiahao ^{[1
]}

Shen, Meiqing ^{[1
,2
]}

Wang, Xinquan ^{[1
]}

Qi, Gongshin ^{[3
]}

Wang, Jun ^{[1
]}

Li, Wei ^{[3
]}

机构：

[1] Tianjin Univ, Sch Chem Engn & Technol, Key Lab Green Chem Technol, State Educ Minist, Tianjin 300072, Peoples R China

[2] Tianjin Univ, State Key Lab Engines, Tianjin 300072, Peoples R China

[3] Gen Motors Global Res & Dev, Chem Sci & Mat Syst Lab, Warren, MI 48090 USA

来源：

APPLIED CATALYSIS B-ENVIRONMENTAL | 2013年 / 134卷

基金：

国家高技术研究发展计划(863计划);

关键词：

NO oxidation; Mn4+/Mn3+ ratio; Nonstoichiometry; LaMnO3; perovskite; METHANE COMBUSTION; STRUCTURAL DEFECTS; CO; LANTHANUM; STORAGE; REDUCTION; PLATINUM; SR; SUBSTITUTION; PERFORMANCE;

D O I：

10.1016/j.apcatb.2013.01.027

中图分类号：

O64 [物理化学（理论化学）、化学物理学];

学科分类号：

070305 [高分子化学与物理];

摘要：

A series of structural modified LaxMnO3 (x = 0.9, 0.95, 1, 1.05, 1.11) perovskites used for NO oxidation was synthesized by a sol-gel method and characterized by XRD, BET, XPS, EPR and H-2-TPR. La0.9MnO3 sample exhibits superior activity, and a 50% NO conversion at 250 degrees C is obtained. XPS and EPR results reveal a higher Mn4+/Mn3+ ratio in Mn-rich samples, which induce more active oxygen bonding to Mn4+ due to the need for balancing the chemical states and stabilizing the structure. Easily regenerated oxygen associated with Mn4+ catalyzes the low-temperature NO oxidation. The constant activation energy (44.8 kJ/mol) obtained in the kinetics tests indicates the same mechanism of NO oxidation operated on all the samples. (C) 2013 Elsevier B.V. All rights reserved.

引用

页码：251 / 257

页数：7

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