Reduction of Mixed Mn–Zr Oxides: In situ XPS and XRD Studies Full article
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Dalton Transactions
ISSN: 1477-9226 , E-ISSN: 1477-9234 |
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| Output data | Year: 2015, Volume: 44, Number: 35, Pages: 15499-15507 Pages count : 9 DOI: 10.1039/C5DT01440A | ||||||
| Tags | RAY PHOTOELECTRON-SPECTROSCOPY; PHOTOIONIZATION CROSS-SECTIONS; THERMAL-STABILITY; TOTAL OXIDATION; CATALYSTS; ZIRCONIA; METHANE; TRANSITION; DIFFRACTION; EVOLUTION | ||||||
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| Affiliations |
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Funding (1)
| 1 | Russian Science Foundation | 14-23-00037 |
Abstract:
A series of mixed Mn–Zr oxides with different molar ratios Mn/Zr (0.1–9) have been prepared by coprecipitation of manganese and zirconium nitrates and characterized by X-ray diffraction (XRD) and BET methods. It has been found that at concentrations of Mn below 30 at%, the samples are single-phase solid solutions (MnxZr1−xO2−δ) based on a ZrO2 structure. X-ray photoelectron spectroscopy (XPS) measurements showed that manganese in these solutions exists mainly in the Mn4+ state on the surface. An increase in Mn content mostly leads to an increase in the number of Mn cations in the structure of solid solutions; however, a part of the manganese cations form Mn2O3 and Mn3O4 in the crystalline and amorphous states. The reduction of these oxides with hydrogen was studied by a temperature-programmed reduction technique, in situ XRD, and near ambient pressure XPS in the temperature range from 100 to 650 °C. It was shown that the reduction of the solid solutions MnxZr1−xO2−δ proceeds via two stages. During the first stage, at temperatures between 100 and 500 °C, the Mn cations incorporated into the solid solutions MnxZr1−xO2−δ undergo partial reduction. During the second stage, at temperatures between 500 and 700 °C, Mn cations segregate on the surface of the solid solution. In the samples with more than 30 at% Mn, the reduction of manganese oxides was observed: Mn2O3 → Mn3O4 → MnO.
Cite:
Bulavchenko O.A.
, Vinokurov Z.S.
, Afonasenko T.N.
, Tsyrulʹnikov P.G.
, Tsybulya S.V.
, Saraev A.A.
, Kaichev V.V.
Reduction of Mixed Mn–Zr Oxides: In situ XPS and XRD Studies
Dalton Transactions. 2015.
V.44. N35. P.15499-15507. DOI: 10.1039/C5DT01440A
WOS
Scopus
РИНЦ
ANCAN
OpenAlex
Reduction of Mixed Mn–Zr Oxides: In situ XPS and XRD Studies
Dalton Transactions. 2015.
V.44. N35. P.15499-15507. DOI: 10.1039/C5DT01440A
WOS
Scopus
РИНЦ
ANCAN
OpenAlex
Files:
Full text from publisher
Dates:
| Submitted: | Apr 16, 2015 |
| Accepted: | Jul 22, 2015 |
| Published print: | Jul 22, 2015 |
| Published online: | Jul 22, 2015 |
Identifiers:
| Web of science: | WOS:000360452600022 |
| Scopus: | 2-s2.0-84940398918 |
| Elibrary: | 24944125 |
| Chemical Abstracts: | 2015:1209556 |
| Chemical Abstracts (print): | 163:311446 |
| OpenAlex: | W2162733257 |