Behavior of some deep oxidation catalysts under extreme conditions. 1. Comparison of resistance to thermal shock and SO2 poisoning

Effect of A-site metal on methane combustion on 2% Pd / AMn1-x Fe x O3 (A = Ba, La, Pr; x = 0.4, 0.6, 1) perovskites

“…It has been suggested that sulfur dioxide reacts with surface oxides [2,3,18,19]. Reaction between SO 2 ) or SO ) species (which can be form during adsorption) and surface oxygen of perovskite generates SO 3 ) radicals, and at high temperatures SO 3 ) radicals may desorb or react further with oxygen to yield SO 4 2) . The interaction between surface sulfate species and perovskite can lead to A-site metal sulfate.…”

“…The interaction between surface sulfate species and perovskite can lead to A-site metal sulfate. The activity of perovskite can be returned by decomposition of sulfur compound at high temperature ( > 900°C) [3]. Figure 2 shows the methane conversion of fresh and SO 2 -treated perovskites at 500°C.…”

“…Pd/Al 2 O 3 is reported to be the most active catalyst for methane oxidation when excess of oxygen is present. The use of perovskites in methane combustion has been investigated, as well [1][2][3][4][5][6][7][8][9][10][11][12][13][14]. The effect on methane combustion of the A-site metal in perovskites has been studied by substituting lanthanum with another metal [1,2,9,15,16].…”

“…The resistance of perovskites to sulfur is dependent on the composition of the A-and B-site metals [2,3,17,18], and different metal combinations have been studied in the hope of improving the resistance of perovskite to sulfur.…”

Study of the interface action between LaCoO3 layer and Al2O3 substrate

“…3,4 It was reported that the addition of rare earth oxides could improve the activity and stability of automotive depollution catalysts. 5,6 The catalyst structure was responsible for the catalytic properties of the rare-earth-promoted catalysts. The additive La 2 O 3 can react with Al 2 O 3 to form surface lanthanum aluminate compounds (LaAlO 3 ).…”