To improve their thermal stability, La0.8Sr0.2MnO3 cordierite monoliths are washcoated with mayenite, which is a novel Al-based material with the crystal structure of 12MO·7Al2O3 (M= Ca, Sr). The monoliths are characterized by means of nitrogen adsorption/desorption, scanning electron microscopy, and X-ray diffraction. Catalytic performances of the monoliths are tested for methyl methacrylate combustion. The results show that mayenite obviously improves both the physic-chemical properties and the catalytic performance of the monoliths. Because mayenite improves the dispersity of La0.8Sr0.2MnO3 and also prevents the interaction between La0.8Sr0.2MnO3 and cordierite or γ-Al2O3, both crystal structure and surface morphology of La0.8Sr0.2MnO3 phase can thereby be stable on the mayenite surface even at high temperature up to 1050 oC. Under the given reaction conditions, La0.8Sr0.2MnO3 monolith washcoated with 12SrO·7Al2O3 shows the best catalytic activity for methyl methacrylate combustion among all the tested monoliths.
Pe?a M A, Fierro J L G. Chemical structures and performance of perovskite oxides. Chemical Reviews , 2001, 101(7): 1981–2017 doi: 10.1021/cr980129f
2
Misono M. A view on the future of mixed oxide catalysts: The case of heteropolyacids (polyoxometalates) and perovskites. Catalysis Today , 2005, 100(1): 95–100 doi: 10.1016/j.cattod.2004.12.010
Avila P, Montes M, Miró E E. Monolithic reactors for environmental applications: A review on preparation technologies. Chemical Engineering Journal , 2005, 109(1): 11–36 doi: 10.1016/j.cej.2005.02.025
5
Cimino S, Colonna S, de Rossi S, Faticanti M, Lisi L, Pettiti I, Porta P. Methane combustion and CO oxidation on zirconia-supported La, Mn oxides and LaMnO3 Perovskite. Journal of Catalysis , 2002, 205(2): 309–317 doi: 10.1006/jcat.2001.3441
6
Cimino S, Pirone R, Russo G. Thermal stability of perovskite-based monolithic reactors in the catalytic combustion of methane. Industrial & Engineering Chemistry Research , 2001, 40(1): 80–85 doi: 10.1021/ie000392i
Stephan K, Hackenberger M, Kie?ling D, Wendt G. Supported perovskite-type oxide catalysts for the total oxidation of chlorinated hydrocarbons. Catalysis Today , 1999, 54(1): 23–30 doi: 10.1016/S0920-5861(99)00164-9
9
Alifanti M, Florea M, Parvulescu V I. Ceria-based oxides as supports for LaCoO3 perovskite catalysts for total oxidation of VOC. Applied Catalysis B: Environmental , 2007, 70(3): 400–405 doi: 10.1016/j.apcatb.2005.10.037
10
Yin F, Ji S, Chen B, Zhao L, Liu H, Li C. Preparation and characterization of LaFe1-xMgxO3/Al2O3/FeCrAl: Catalytic properties in methane combustion. Applied Catalysis B: Environmental , 2006, 66(2): 265–273 doi: 10.1016/j.apcatb.2006.03.017
11
Fabbrini L, Rossetti I, Forni L. Effect of primer on honeycomb-supported La0.9Ce0.1CoO3 perovskite for methane catalytic flameless combustion. Applied Catalysis B: Environmental , 2003, 44(1): 107–116 doi: 10.1016/S0926-3373(03)00025-0
12
Arendt E, Maione A, Klisinska A, Sanz O, Montes M, Suarez S, Blanco J, Ruiz P. Structuration of LaMnO3 perovskite catalysts on ceramic and metallic monoliths: Physico-chemical characterisation and catalytic activity in methane combustion. Applied Catalysis A, General , 2008, 339(1): 1–14 doi: 10.1016/j.apcata.2008.01.016
13
Zou H, Ge X, Shen J. Preparation and catalytic properties of solid base catalysts I. Metal Oxides. Thermochimica Acta , 2003, 397(1): 81–86 doi: 10.1016/S0040-6031(02)00329-5
14
Yamamoto T, Hatsui T, Matsuyama T, Tanaka T, Funabiki T. Structures and acid-base properties of La/Al2O3 role of La addition to enhance thermal stability of γ-Al2O3. Chemistry of Materials , 2003, 15(25): 4830–4840 doi: 10.1021/cm034732c
15
Yamamoto T, Tanaka T, Matsuyama T, Funabiki T, Yoshida S. Structural analysis of La/Al2O3 catalysts by La K-edge XAFS. Journal of Synchrotron Radiation , 2001, 8(2): 634–636 doi: 10.1107/S0909049500017106
16
Zwinkels M F M, Haussner O, Menon P G, J?r?s S. Preparation and characterization of LaCrO3 and Cr2O3 methane combustion catalysts supported on LaAl11O18 and Al2O3-coated monoliths. Catalysis Today , 1999, 47(1): 73–82 doi: 10.1016/S0920-5861(98)00284-3
17
Hayashi K, Matsuishi S, Hirano M, Hosono H. Formation of oxygen radicals in 12CaO·7Al2O3: Instability of extraframework oxide ions and uptake of oxygen gas. Journal of Physical Chemistry B , 2004, 108(26): 8920–8925 doi: 10.1021/jp037916n
18
Li C, Hirabayashi D, Suzuki K. A crucial role of O2- and O22- on mayenite structure for biomass tar steam reforming over Ni/Ca12Al14O33. Applied Catalysis B: Environmental , 2009, 88(3): 351–360 doi: 10.1016/j.apcatb.2008.11.004
19
Yang S, Kondo J, Hayashi K, Hirano M, Domen K, Hosono H. Formation and desorption of oxygen species in nanoporous crystal 12CaO·7Al2O3. Chemistry of Materials , 2004, 16(1): 104–110 doi: 10.1021/cm034755r
20
Hayashi K, Ueda N, Matsuishi S, Hirano M, Kamiya T, Hosono H. Solid state syntheses of 12SrO·7Al2O3 and formation of high density oxygen radical anions, O- and O2-. Chemistry of Materials , 2008, 20(19): 5987–5996 doi: 10.1021/cm800666p
21
Banús E D, Milt V G, Miró E E, Ulla M A. Structured catalyst for the catalytic combustion of soot: Co, Ba, K/ZrO2 supported on Al2O3 foam. Applied Catalysis A, General , 2009, 362(1): 129–138 doi: 10.1016/j.apcata.2009.04.035
22
Stutz M J, Poulikakos D. Optimum washcoat thickness of a monolith reactor for syngas production by partial oxidation of methane. Chemical Engineering Science , 2008, 63(7): 1761–1770 doi: 10.1016/j.ces.2007.11.032
