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Thermal stability of Pd-containing LaAlO3 perovskite as a modern TWC

“…However, the LaAlO 3 -based Pd(0.8)-600 catalysts have smaller amounts of PdO than Pd(0.8)/Al 2 O 3 -600 due to their higher electron density of Pd by the electron donation from La [32]. Indeed, the lower electronegativity of La than Pd results in the formation of the less-oxidized PdO 1Àx species on the catalysts surface with the low oxidation state of Pd, as also observed in the XPS results [34]. The distribution of the Pd species on the catalyst surface is notably altered by the increase of aging temperature.…”

“…However, the BE of the Pd 3d 5/2 for Pd(0.8)/LaAlO 3 -600 shifts to a lower BE compared to that for the Al 2 O 3 -based Pd-600 catalysts and a further shift is observed over LaAlPd(0.8)O 3 -600, indicating the formation of the less oxidized PdO 1Àx species on the surface of the perovskite-based catalyst [32,34]. This BE of LaAlPdO 3 -600 remains nearly constant with the increase of the catalyst Pd loading from 0.8 to 2.4 wt.%, as shown in Table 2 and Fig.…”

“…S7 of Supplementary Material). As listed in Table 2, the binding energy (BE) of the Pd 3d 5/2 for both Pd(0.8)/Al 2 O 3 -600 and Al 2 Pd(0.8)O 3 -600 is 335.8 eV, indicating that the Pd may exist in a state between PdO (336.5 eV) and Pd 0 (335.1 eV) [32][33][34].…”

Phase Analysis and Oxygen Storage Capacity of Ceria-Lanthana-Based TWC Promoters Prepared by Sol–Gel Routes

“…Actually, a high thermal stability is an essential requirement for the CeO containing supports, since in automotive applications the converter is close to the engine, and temperatures of about 10003C can be reached. Only a limited number of studies are concerned with ceria}lan-thana mixed oxides supported on alumina (2,3,9,10). It is evident that the net result of combining La> with CeO and Al O is not easy to anticipate, due to the strong dependence of the structure and of the redox behavior on the employed synthetic route.…”

Chemical Characterization and Catalytic Activity of Pd-Supported Catalysts on Ce0.39Zr0.61O x /SiO2

“…The XRD diagram of Ce/Si catalyst (Fig. 1a) presented four sharp peaks, one at 28.7°, which is attributed to the (1 1 1) plane of fluorite structure of CeO 2 and the other three centered at 33.2, 47.6 and 56.2°correspond to high order reflections of CeO 2 [21,22]. CeZr mixed oxide was formed by the impregnation method, as indicated by the shift of the (1 1 1) peak to higher angles (Fig.…”