Pd–Cu interaction in Pd/Cu-MCM-41 catalysts: Effect of silica source and metal content

Advanced Pd/CexZr(1−x)O2/MCM-41 catalysts for methane combustion: Effect of the zirconium and cerium loadings

“…This reduction step seems to occur at negative temperature since it is not registered on the TPR profile. This result is in agreement with the literature [24,25] which suggested that large PdO x species supported on SiO 2 could be reduced at low temperatures. In addition, it was established [25] that Pd crystallites adsorb hydrogen to form PdH x species, which decompose by the temperature increase.…”

Amino-modified molecular sieves for adsorptive removal of H2S from natural gas

“…1). 18,19 The peak corresponding to the (100) plane could be considered as a feature of the MCM-41 mesostructure, indicating that the hexagonal mesoporous structure of MCM-41 was preserved aer being loaded with APTMS, PEI or AAPTS. However, the (100) plane of the modied MCM-41 adsorbents was weaker compared with that of bare MCM-41, and even the peaks of other planes disappeared.…”

In-situ X-ray absorption study of ceria-supported Pd-Cu nanoparticles for oxygen-enhanced water gas shift

“…The surface enrichment is due partly to the lower surface free energy of Cu than Pd [30,31]. This also occurs on SiO 2 [20,31] and MCM-41 [26], but lesser extent. For Pd-Cu/C prepared by a polyol method with citric acid stabilizer, Pd was more on the surface [32].…”

“…4 nm), which was realized by the preparation condition using palladium acetate as a metal source. Cu shifts to lower energy by Pd addition [24][25][26][27]. Some reports concluded that the charge moves from Pd to Cu based on XPS measurements while the others accounted the experimental results for hybridation and polarization of orbitals.…”