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Perovskites as Alternatives to Noble Metals in Automotive Exhaust Abatement: Activation of Oxygen on LaCrO3 and LaMnO3
被引:28
作者:
Peron, G.
[1
]
Glisenti, A.
[1
,2
]
机构:
[1] Univ Padua, Dept Chem Sci, Via F Marzolo 1, I-35131 Padua, Italy
[2] CNR ICMATE, Via F Marzolo 1, I-35131 Padua, Italy
关键词:
Lanthanum chromite;
Lanthanum manganate;
Perovskite;
Soot oxidation;
NO reduction;
K-doping;
DIESEL SOOT;
CATALYTIC-ACTIVITY;
SIMULTANEOUS REMOVAL;
SURFACE-PROPERTIES;
PERFORMANCE;
COMBUSTION;
OXIDATION;
OXIDE;
KINETICS;
NOX;
D O I:
10.1007/s11244-018-1120-1
中图分类号:
O69 [应用化学];
学科分类号:
081704 ;
摘要:
In this contribution, perovskitic materials have been tested as substitutes of noble metals in automotive exhaust abatement devices. LaMnO3 and LaCrO3 were the chosen materials. Samples were characterized by means of X-ray diffraction, scanning electron microscopy, BET surface area, temperature programmed reduction and X-ray photoelectron spectroscopy. Reactions tested have been soot oxidation by 10% O-2 and 0.5% NO and stoichiometric 1% NO reduction by 1% CO. LaMnO3 has proved to be a good catalyst for oxidation reactions, whereas LaCrO3 is more suitable for reduction reactions. TPR and XPS analysis have shown a greater oxygen exchange capability in LaMnO3 than in LaCrO3, which is less reducible and strongly bonds adsorbed oxygen. Substitution of 20% La in the A-site of the perovskitic lattice with K has increased activity of both catalysts. In the case of LaCrO3, however, this has lead to a slower reaction course. NO reduction test clearly indicates that Cr-containing perovskite is more suitable for reduction reactions, whereas Mn-based materials are a good choice for oxidative applications. This can relate to superficial oxygen properties and bulk oxygen mobility, as shown by XPS and TPR results.
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页码:244 / 251
页数:8
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