scispace - formally typeset
Search or ask a question
Topic

Cerium

About: Cerium is a research topic. Over the lifetime, 17616 publications have been published within this topic receiving 259152 citations. The topic is also known as: Ce & element 58.


Papers
More filters
Journal ArticleDOI
TL;DR: In this article, an XPS study of Ce 3D emission spectra dominated by atomic multiplet effects in core level spectroscopy of rare earth compounds (Ce oxides) was presented.
Abstract: This article presents an XPS study of Ce 3d emission spectra dominated by atomic multiplet effects in core level spectroscopy of rare earth compounds (Ce oxides). Core level spectroscopy has been used to study the electronic states of Ce 3d5/2 and Ce 3d3/2 levels in Ce4+ and Ce3+ states. The well-resolved components of Ce 3d5/2 and Ce 3d3/2 spin-orbit components, due to various final states (4f0, 4f1, 4f2 configurations), were determined on 3d XPS spectra from commercial powders (CeO2, CePO4). These results were used to study the 3d spin-orbit component of mixed cerium-titanium oxide. This compound was prepared by co-melting commercial powders of CeO2 and TiO2 at 1800 K under air using a solar furnace with a flux density of 16 MW.m−2 at the focal point of the parabolic concentrator. The mixed oxide Ce2Ti2O7 was produced and contained Ce(III) species which may be reactive with water to give back the initial metal oxides and generate hydrogen, a valuable product considered as a promising energy carrier in the future in replacement of oil. The 3d photoemission spectra revealed the presence of mixed components attributed to mainly Ce(III) and Ce(IV) species. Copyright © 2008 John Wiley & Sons, Ltd.

846 citations

Journal ArticleDOI
TL;DR: In this paper, a study of the core-electron X-ray photoelectron (X-p) spectra of the f0 compounds La2O3, LaMO3(M = Fe and Co), CeO2, and BaCeO3 is described.
Abstract: A study of the core-electron X-ray photoelectron (X-p.e.) spectra of the f0 compounds La2O3, LaMO3(M = Fe and Co), CeO2, and BaCeO3 is described. Results on the chelate species [La(tmhd)3] and [Ce(tmhd)4](tmhd = 2,2,6,6-tetramethylheptane-3,5-dionato) are included for comparison. Special precautions have been taken to ensure an optimal degree of surface purity of the samples. Satellite structure has been observed for the 4p, in addition to the 3d and 4d, signals in both the lanthanum(III) and cerium(IV) compounds. These satellites arc discussed in terms of coexcitations of the charge-transfer type, principally O 2p→ metal 4f transitions. In the cerium(IV) oxides the satellites are apparently due to energy-gain (representing ‘ shake-down ’) rather than energy-loss (shake-up) processes.

841 citations

Journal ArticleDOI
20 Aug 2010-Science
TL;DR: An analysis of previous calorimetry data for silver nanoparticles on magnesium oxides and cerium oxide surfaces is presented and it is shown that nanoparticles smaller than 1000 atoms are bound much more strongly to reduced Cerium oxide.
Abstract: The energies of silver (Ag) atoms in Ag nanoparticles supported on different cerium and magnesium oxide surfaces, determined from previous calorimetric measurements of metal adsorption energies, were analyzed with respect to particle size. Their stability was found to increase with particle size below 5000 atoms per particle. Silver nanoparticles of any given size below 1000 atoms had much higher stability (30 to 70 kilojoules per mole of silver atoms) on reduced CeO2(111) than on MgO(100). This effect is the result of the very large adhesion energy (approximately 2.3 joules per square meter) of Ag nanoparticles to reduced CeO2(111), which we found to be a result of strong bonding to both defects and CeO2(111) terraces, apparently localized by lattice strain. These results explain the unusual sinter resistance of late transition metal catalysts when supported on ceria.

742 citations

Journal ArticleDOI
01 Apr 2016-Science
TL;DR: It is demonstrated how the lanthanide contraction can be used to control strain effects and tune the activity, stability, and reactivity of these materials.
Abstract: The high platinum loadings required to compensate for the slow kinetics of the oxygen reduction reaction (ORR) impede the widespread uptake of low-temperature fuel cells in automotive vehicles. We have studied the ORR on eight platinum (Pt)–lanthanide and Pt-alkaline earth electrodes, Pt5M, where M is lanthanum, cerium, samarium, gadolinium, terbium, dysprosium, thulium, or calcium. The materials are among the most active polycrystalline Pt-based catalysts reported, presenting activity enhancement by a factor of 3 to 6 over Pt. The active phase consists of a Pt overlayer formed by acid leaching. The ORR activity versus the bulk lattice parameter follows a high peaked “volcano” relation. We demonstrate how the lanthanide contraction can be used to control strain effects and tune the activity, stability, and reactivity of these materials.

693 citations

Journal ArticleDOI
TL;DR: In this paper, the preparation of sodium phosphate glasses singly and doubly doped with rare earth ion Ce 3+ and transition metal ion Mn 2+ by a melt quench method is described.

684 citations


Network Information
Related Topics (5)
Oxide
213.4K papers, 3.6M citations
92% related
Raman spectroscopy
122.6K papers, 2.8M citations
89% related
Aqueous solution
189.5K papers, 3.4M citations
88% related
Adsorption
226.4K papers, 5.9M citations
87% related
Carbon
129.8K papers, 2.7M citations
87% related
Performance
Metrics
No. of papers in the topic in previous years
YearPapers
2023577
20221,112
2021534
2020614
2019734
2018747