The electronic and reduction properties of Ce0.75Zr0.25O2(110)

Yang, Zhou; Fu, Zhaoming; Wei, Yanwei; Hermansson, Kersti

doi:10.1016/j.cplett.2007.11.026

Cited by 26 publications

(26 citation statements)

References 22 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…35. A very similar structure was presented for a Zr-doped ceria (110) surface by Yang et al 36 In the third structure, the surface oxygen ion coordinated to the two cerium ions neighbouring the vacancy is again displaced towards the vacancy but this time moves less far, and remains within the plane of the surface layer; see Fig. 1(b).…”

Section: Introductionmentioning

confidence: 65%

“…This symmetrical in-plane (s-InPl) structure has been found using DFT with LDA+U, 20 PW91+U 19 and PBE+U. 20,36,37 In comparing the three structures in this paper, we find that a large part of the difficulty in identifying the relative stabilities of these vacancy structures is related to the choice of periodic supercells used for the calculations, which, as we will show, have often been too small to uniquely contain the various important different localization patterns. All but one of the DFT-based studies in Table I used only the p(2 × 1) and/or p(2 × 2) supercells, i.e., 2 or 4 repeats of the basic (110) surface unit cell.…”

Section: Introductionmentioning

confidence: 97%

See 1 more Smart Citation

Many competing ceria (110) oxygen vacancy structures: From small to large supercells

Kullgren

Hermansson

Castleton

2012

The Journal of Chemical Physics

Self Cite

View full text Add to dashboard Cite

We present periodic "DFT+U" studies of single oxygen vacancies on the CeO 2 (110) surface using a number of different supercells, finding a range of different local minimum structures for the vacancy and its two accompanying Ce(III) ions. We find three different geometrical structures in combination with a variety of different Ce(III) localization patterns, several of which have not been studied before. The desired trapping of electrons was achieved in a two-stage optimization procedure. We find that the surface oxygen nearest to the vacancy either moves within the plane towards the vacancy, or rises out of the surface into either a symmetric or an unsymmetric bridge structure. Results are shown in seven slab geometry supercells, p(2 × 1), p(2 × 2), p(2 × 3), p(3 × 2), p(2 × 4), p(4 × 2), and p(3 × 3), and indicate that the choice of supercell can affect the results qualitatively and quantitatively. An unsymmetric bridge structure with one nearest and one next-nearest neighbour Ce(III) ion (a combination of localizations not previously found) is the ground state in all (but one) of the supercells studied here, and the relative stability of other structures depends strongly on supercell size. Within any one supercell the formation energies of the different vacancy structures differ by up to 0.5 eV, but the same structure can vary by up to ∼1 eV between supercells. Furthermore, finite size scaling suggests that the remaining errors (compared to still larger supercells) can also be ∼1 eV for some vacancy structures.

show abstract

Section: Introductionmentioning

confidence: 65%

Section: Introductionmentioning

confidence: 97%

Many competing ceria (110) oxygen vacancy structures: From small to large supercells

Kullgren

Hermansson

Castleton

2012

The Journal of Chemical Physics

Self Cite

View full text Add to dashboard Cite

show abstract

“…Similarly to the experimental studies, some of the dopants that have been thoroughly examined are Au [20,22,23], Cu [3,24,26], Pd [3,21,25,[27][28][29], and Zr [1,16,34,35], with concentration on surface reducibility as well as CO, CH 4 , H 2 , or H 2 O interactions with the surface. Using Au as a dopant in the CeO 2 lattice for CO oxidation allows the surface oxygen atoms to become reactive, but not too reactive that the oxygen vacancies will not heal.…”

Section: Introductionmentioning

confidence: 99%

“…When Zr is doped into the lattice of CeO 2 , it takes on a Zr 4+ oxidation state [1]. Upon the formation of a surface oxygen vacancy, two cerium atoms reduce rather than the zirconia [34]. High-valence dopants have only a local effect on oxygen atoms next to them, whereas low-valence dopants have both long-and short-range effects [37].…”

Section: Introductionmentioning

confidence: 99%

Periodic trends of oxygen vacancy formation and C–H bond activation over transition metal-doped CeO2 (1 1 1) surfaces

Krcha

Mayernick

Janik

2012

Journal of Catalysis

158

206

View full text Add to dashboard Cite

“…These results clearly demonstrate the morphology effect of ceria-zirconia solid solutions, regularly tubular morphology are most active. The Ce 4+ /Ce 3+ redox cycle could be more easily generated on the nanorods due to lower surface reduction energy of ceria on the 110 plane in previous literature [36][37][38]. ceria-zirconia solid solutions ranked in the following sequence: leaves/CZ50 (1976 μmol/g) > stems/CZ50 (1173 μmol/g) > stem-silk/CZ50 (1089 μmol/g) > CZ50 (999 μmol/g).…”

Section: Oxygen Storage Capacitymentioning

confidence: 99%

Noble Metal-Free Ceria-Zirconia Solid Solutions Templated by Tobacco Materials for Catalytic Oxidation of CO

et al. 2016

View full text Add to dashboard Cite

A series of ceria-zirconia solid solutions were synthesized using tobacco leaves, stems and stem-silks as biotemplates. A combination of physicochemical techniques such as powder X-ray diffraction (XRD), N 2 adsorption/desorption measurement, scanning electron microscopy (SEM), and transmission electron microscopy (TEM) were used to characterize the as-synthesized samples. The results show that the morphologies of the templates were well replicated in the obtained ceria-zirconia solid solutions. Catalytic oxidation activities of CO over the ceria-zirconia solid solutions were then investigated. The catalyst templated by tobacco stem-silk exhibited higher conversion of CO at lower temperature than that of ceria-zirconia solid solutions templated by tobacco leaves and stems or without templates due to its special morphology. The catalyst even showed similar CO conversion when compared to ceria-zirconia solid solutions doped with 1.0 wt % noble metals such as Pt, Ag and Au. The results highlighted the advantages of using tobacco as biotemplate.

show abstract

The electronic and reduction properties of Ce0.75Zr0.25O2(110)

Cited by 26 publications

References 22 publications

Many competing ceria (110) oxygen vacancy structures: From small to large supercells

Many competing ceria (110) oxygen vacancy structures: From small to large supercells

Periodic trends of oxygen vacancy formation and C–H bond activation over transition metal-doped CeO2 (1 1 1) surfaces

Noble Metal-Free Ceria-Zirconia Solid Solutions Templated by Tobacco Materials for Catalytic Oxidation of CO

Contact Info

Product

Resources

About