Nonstoichiometric Oxygen in Mn–Ga–O Spinels: Reduction Features of the Oxides and Their Catalytic Activity | Sciact - CRIS-система Института катализа

Nonstoichiometric Oxygen in Mn–Ga–O Spinels: Reduction Features of the Oxides and Their Catalytic Activity Научная публикация

Журнал

RSC Advances
ISSN: 2046-2069

Вых. Данные

Год: 2018, Том: 8, Номер: 21, Страницы: 11598-11607 Страниц : 10 DOI: 10.1039/c7ra11557a

Ключевые слова

THIN-FILMS; MANGANESE OXIDES; CO OXIDATION; NANOPARTICLES; TEMPERATURE; PERFORMANCE; COMBUSTION; MN2O3

Авторы

Bulavchenko O. A. ^1,2 , Venediktova O. S. ^1,2 , Afonasenko T. N. ³ , Tsyrul'nikov P. G. ³ , Saraev A. A. ^1,2 , Kaichev V. V. ^1,2 , Tsybulya S. V. ^1,2

Организации

1	Boreskov Institute of Catalysis SB RAS, Lavrentieva Ave. 5, Novosibirsk, 630090, Russia
2	Novosibirsk State University, Pirogova Str. 2, Novosibirsk, 630090, Russia
3	Institute of Hydrocarbons Processing SB RAS, Neftezavodskaya Str. 54, Omsk, 644040, Russia

Информация о финансировании (1)

Федеральное агентство научных организаций России

0303-2016-0002

The subject of this study was the content of oxygen in mixed oxides with the spinel structure Mn1.7Ga1.3O4 that were synthesized by coprecipitation and thermal treatment in argon at 600–1200 °C. The study revealed the presence of excess oxygen in “low-temperature” oxides synthesized at 600–800 °C. The occurrence of superstoichiometric oxygen in the structure of Mn1.7Ga1.3O4+δ oxide indicates the formation of cationic vacancies, which shows up as a decreased lattice parameter in comparison with “high-temperature” oxides synthesized at 1000–1200 °C; the additional negative charge is compensated by an increased content of Mn3+ cations according to XPS. The low-temperature oxides containing excess oxygen show a higher catalytic activity in CO oxidation as compared to the high-temperature oxides, the reaction temperature was 275 °C. For oxides prepared at 600 and 800 °C, catalytic activity was 0.0278 and 0.0048 cm3 (CO) per g per s, and further increase in synthesis temperature leads to a drop in activity to zero. The process of oxygen loss by Mn1.7Ga1.3O4+δ was studied in detail by TPR, in situ XRD and XPS. It was found that the hydrogen reduction of Mn1.7Ga1.3O4+δ proceeds in two steps. In the first step, excess oxygen is removed, Mn1.7Ga1.3O4+δ → Mn1.7Ga1.3O4. In the second step, Mn3+ cations are reduced to Mn2+ in the spinel structure with a release of manganese oxide as a single crystal phase, Mn1.7Ga1.3O4 → Mn2Ga1O4 + MnO.

Bulavchenko O.A. , Venediktova O.S. , Afonasenko T.N. , Tsyrul'nikov P.G. , Saraev A.A. , Kaichev V.V. , Tsybulya S.V.
Nonstoichiometric Oxygen in Mn–Ga–O Spinels: Reduction Features of the Oxides and Their Catalytic Activity

RSC Advances. 2018. V.8. N21. P.11598-11607. DOI: 10.1039/c7ra11557a WOS Scopus РИНЦ CAPlus PMID OpenAlex

Полный текст от издателя

Поступила в редакцию:	19 окт. 2017 г.
Принята к публикации:	9 мар. 2018 г.
Опубликована online:	27 мар. 2018 г.

Web of science:	WOS:000428672500041
Scopus:	2-s2.0-85044627083
РИНЦ:	35488796
Chemical Abstracts:	2018:602427
PMID (PubMed):	35542767
OpenAlex:	W2794568465

БД	Цитирований
Web of science	22
Scopus	22
РИНЦ	21
OpenAlex	25