Dataset Information

Enhanced properties of Pd/CeO₂-nanorods modified with alkaline-earth metals for catalytic oxidation of low-concentration methane.

ABSTRACT: A series of Pd/CeO₂-nanorods catalysts modified with alkaline-earth metals were prepared by the incipient impregnation method. Their catalytic properties in low-concentration methane oxidation were also investigated. The catalysts were characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy and H₂-temperature-programmed reduction techniques. The catalytic results show that the Ca element doped in Pd/CeO₂, with optimum molar ratio of Pd to Ca of 2 and calcination temperature of 450 °C, improved the properties of the Pd-based catalyst remarkably, which is attributed to strong Pd-support interaction and high oxygen mobility. Therefore, calcium is more suitable as a promoter for enhancing the activities of the Pd/CeO₂ catalyst in methane oxidation.

SUBMITTER: Guo T

PROVIDER: S-EPMC9090572 | biostudies-literature | 2018 Nov

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Enhanced properties of Pd/CeO2-nanorods modified with alkaline-earth metals for catalytic oxidation of low-concentration methane.

Guo Tianyu T Nie Xiaorong X Du Jianping J Li Jinping J

RSC advances 20181116 67

A series of Pd/CeO2-nanorods catalysts modified with alkaline-earth metals were prepared by the incipient impregnation method. Their catalytic properties in low-concentration methane oxidation were also investigated. The catalysts were characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy and H2-temperature-programmed reduction techniques. The catalytic results show that the Ca element doped in Pd/CeO2, with optimum mo ...[more]

PMID: 35559059

Similar Datasets

Project description:CO elimination through oxidation over highly active and cost-effective catalysts is a way forward for many processes of industrial and environmental importance. In this study, doped CeO2 with transition metals (TM = Cu, Co, Mn, Fe, Ni, Zr, and Zn) at a level of 20 at. % was tested for CO oxidation. The oxides were prepared using microwave-assisted sol-gel synthesis to improve catalyst's performance for the reaction of interest. The effect of heteroatoms on the physicochemical properties (structure, morphology, porosity, and reducibility) of the binary oxides M-Ce-O was meticulously investigated and correlated to their CO oxidation activity. It was found that the catalytic activity (per gram basis or TOF, s-1) follows the order Cu-Ce-O > Ce-Co-O > Ni-Ce-O > Mn-Ce-O > Fe-Ce-O > Ce-Zn-O > CeO2. Participation of mobile lattice oxygen species in the CO/O2 reaction does occur, the extent of which is heteroatom-dependent. For that, state-of-the-art transient isotopic 18O-labeled experiments involving 16O/18O exchange followed by step-gas CO/Ar or CO/O2/Ar switches were used to quantify the contribution of lattice oxygen to the reaction. SSITKA-DRIFTS studies probed the formation of carbonates while validating the Mars-van Krevelen (MvK) mechanism. Scanning transmission electron microscopy-high-angle annular dark field imaging coupled with energy-dispersive spectroscopy proved that the elemental composition of dopants in the individual nanoparticle of ceria is less than their composition at a larger scale, allowing the assessment of the doping efficacy. Despite the similar structural features of the catalysts, a clear difference in the Olattice mobility was also found as well as its participation (as expressed with the α descriptor) in the reaction, following the order αCu > αCo> αMn > αZn. Kinetic studies showed that it is rather the pre-exponential (entropic) factor and not the lowering of activation energy that justifies the order of activity of the solids. DFT calculations showed that the adsorption of CO on the Cu-doped CeO2 surface is more favorable (-16.63 eV), followed by Co, Mn, Zn (-14.46, -4.90, and -4.24 eV, respectively), and pure CeO2 (-0.63 eV). Also, copper compensates almost three times more charge (0.37e-) compared to Co and Mn, ca. 0.13e- and 0.10e-, respectively, corroborating for its tendency to be reduced. Surface analysis (X-ray photoelectron spectroscopy), apart from the oxidation state of the elements, revealed a heteroatom-ceria surface interaction (Oa species) of different extents and of different populations of Oa species.

Dataset Information

Enhanced properties of Pd/CeO₂-nanorods modified with alkaline-earth metals for catalytic oxidation of low-concentration methane.

Publications

Enhanced properties of Pd/CeO<sub>2</sub>-nanorods modified with alkaline-earth metals for catalytic oxidation of low-concentration methane.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets