The influence of Mn-doped CeO2 on the activity of CuO/CeO2 in CO oxidation and NO + CO model reaction

Rational Design of Transition Metal Co‐Doped Ceria Catalysts for Low‐Temperature CO Oxidation

“…The XPS spectrum (Figure S6a) of Cu 2p showed a sharp peak of Cu + at 932.4 eV with satellite peaks, and only a small amount of Cu 2+ was present . Importantly, metallic Cu was not observed; this result corresponds to the XRD and Raman results, indicating that the dopant ion does not form an oxide at the catalyst surface .…”

“…The Ce 3+ state is usually obtained by releasing oxygen ions from the Ce 4+ state at the surface, so the catalytic activity can also be predicted by calculating the amount of Ce 3+ in Figure a; this amount is proportional to that of surface oxygen species (Figure b, O surface ) directly involved in the reaction (Table S2) . The proportion of Ce 3+ was 17.20 % of total cerium ions in (Cu, Ag)‐doped CeO 2 and 15.92 % in Cu‐doped CeO 2 (Table S3) . This result corresponds to the Raman spectra; both results indicate that V O form more easily on (Cu, Ag)‐doped CeO 2 than on Cu‐doped CeO 2 .…”

“…Meanwhile, the presence of the weak band at 294 cm −1 in 5CuO/CeO 2 has previously been reported to be related to the presence of crystalline CuO . Deng et al also observed peaks of CuO at 298, 439, and 629 cm −1 , suggesting that CuO crystals are formed on the surface of the support . RuO 2 has been shown to cause bands at 528, 644, and 716 cm −1 , while Qu et al showed that, when AgO exists, the peak near ∼600 cm −1 differentially shifts to 523 cm −1 or 536 cm −1 depending on the template method used .…”

“…Therefore, ceria (CeO 2 ) catalyst was selected as a support, because it has a Ce 4+ /Ce 3+ redox system that gives it high oxygen storage capacity, as well as high density of oxygen‐vacancy defects (V O ) . CeO 2 is a good support in CO oxidation, NO x reduction, and water‐gas shift reactions, and this support has been used to improve catalytic activity …”

Design of Ceria Catalysts for Low‐Temperature CO Oxidation

“…Deng et al reported that the Ce-to-Mn ratio of 10 : 1 showed the highest ratio of Ce 3 + on the surface and the highest activity, and excessive amount of Mn leads to uneven secondary phase and decreased positive effect of MnÀ Ce, suggesting there is an optimum doping concentration. [130] Therefore, metal atoms are uniformly doped into CeO 2 by using appropriate amounts of metal. In terms of activity, higher ratio of Cu + and Ce 3 + were observed in Cu-loaded CeÀ MnO x , which shows high activity.…”