Miran, H.A., Altarawneh, M., Widjaja, H., Jaf, Z.N., Rahman, M.M., Veder, J.P., Dlugogorski, B.Z. and Jiang, Z-T
الملخص الانجليزي
This contribution investigates the effect of the addition of the Hubbard U parameter on the electronic structural
and mechanical properties of cubic (C-type) lanthanide sesquioxides (Ln2O3). Calculated Bader's charges confirm
the ionic character of LneO bonds in the C-type Ln2O3. Estimated structural parameters (i.e., lattice constants)
coincide with analogous experimental values. The calculated band gaps energies at the Ueff of 5 eV for these
compounds exhibit a non-metallic character and Ueff of 6.5 eV reproduces the analogous experimental band gap
of cerium sesquioxide Ce2O3. We have thoroughly investigated the effect of the O/Ce ratios and the effect of
hafnium (Hf) and zirconium (Zr) dopants on the reduction energies of CeOx configurations. Our analysis for the
reduction energy of CeO2, over a wide range of temperatures displays that, shuffling between the two +4 and
+3 oxidation states of Ce exhibit a temperature-independent behaviour. Higher O/Ce ratios necessitate lower
reduction energies. Our results on CeeHfeZreO alloys are in reasonable agreements with analogous fitted
values pertinent to lowering reduction energies and shrinkage in lattice parameters when contrasted with pure
CeO2. Structural analysis reveals that Hf and Zr atoms in the solid solution are shifted towards the nearest
vacancies upon reduction. It is hoped that values provided herein to shed an atomic-base insight into the reduction/
oxidation thermodynamics of increasingly deployed catalysts for environmental applications.
تاريخ النشر
01/05/2018
الناشر
ELSEVIER
رقم المجلد
653
رقم العدد
ISSN/ISBN
0040-6090
رابط DOI
https:// doi.org/10.1016/j.tsf.2018.01.063
الصفحات
12
الكلمات المفتاحية
Lanthanum oxide, Density functional theory, Reduction energy, Mechanical stability
حسين علي جان ميران | Hussein Ali Jan Miran | 2720