FTIR Spectroscopic Study of Titanium-Containing Mesoporous Silicate Materials | Sciact - CRIS-система Института катализа

FTIR Spectroscopic Study of Titanium-Containing Mesoporous Silicate Materials Научная публикация

Журнал

Langmuir
ISSN: 0743-7463 , E-ISSN: 1520-5827

Вых. Данные

Год: 2005, Том: 21, Номер: 23, Страницы: 10545-10554 Страниц : 10 DOI: 10.1021/la0514516

Ключевые слова

MOLECULAR-SIEVES; THIOETHER OXIDATIONS; CATALYTIC-ACTIVITY; SURFACE-ACIDITY; TS-1 CATALYSTS; Ti(IV) CENTERS; Ti-SILICALITE; CO ADSORPTION; NH3; IR

Авторы

Trukhan Natalia N. ¹ , Panchenko Alexander A. ¹ , Roduner Emil ¹ , Mel'gunov Maxim S. ² , Kholdeeva Oxana A. ² , Mrowiec-Białoń Julita ³ , Jarzębski Andrzej B. ⁴

Организации

1	Institute of Physical Chemistry, Stuttgart University, Pfaffenwaldring 55, D-70569 Stuttgart, Germany
2	Boreskov Institute of Catalysis, Acad. Lavrentiev Av. 5, 630090 Novosibirsk, Russia
3	Institute of Chemical Engineering, Polish Academy of Sciences, Bałtycka 5, 44-100 Gliwice, Poland
4	Department of Chemical Engineering, Silesian University of Technology, M. Strzody 7, 44-100 Gliwice, Poland

The surface acidity of different mesoporous titanium−silicates, such as well-organized hexagonally packed Ti−MMM, Ti−MMM-2, Ti−SBA-15, and amorphous TiO2−SiO2 mixed oxides (aerogels and xerogels), was studied by means of FTIR spectroscopy of CO adsorbed at 80 K and CD3CN adsorbed at 293 K. The surface hydroxyl groups of mesoporous titanium-silicates with 2−7 wt % Ti revealed a Brönsted acidity slightly higher to that of pure silicate. TiO2−SiO2 xerogels revealed the highest Brönsted acidity among the titanium−silicates studied. CO adsorption revealed two additional sites on the surface in comparison to pure silicate, characterized by ν(CO) from 2185 (high pressure) to 2178 (low pressure) cm-1 and from 2174 (high pressure) to 2170 (low pressure) cm-1. These bands are due to CO adsorbed on isolated titanium cations in the silica surrounding or having one Ti4+ cation in their second coordination sphere and due to CO interactions with Ti−OH groups, respectively. CD3CN adsorption similarly revealed the existence of two additional sites, which were not detected for pure silicate: at 2289 cm-1 due to CD3CN interaction with titanol groups and from 2306 (low pressure) to 2300 (high pressure) cm-1 due to acetonitrile interaction with isolated framework titanium cations with probably one Ti4+ cation in their second coordination shell. The spectroscopic results are compared with computational data obtained on cluster models of titanium−silicate with different titanium content. According to the IR data, the Ti accessibility on the surfaces for mesoporous titanium−silicates with similar Ti loading (2 wt %) was found to fall in the order TiO2−SiO2 aerogel ∼ TiO2−SiO2 xerogel > Ti−MMM ∼ Ti−MMM-2 > Ti−SBA-15. This order (except TiO2−SiO2 xerogel) correlates with the catalytic activity found previously for titanium−silicates in 2,3,6-trimethylphenol oxidation with H2O2.

Trukhan N.N. , Panchenko A.A. , Roduner E. , Mel'gunov M.S. , Kholdeeva O.A. , Mrowiec-Białoń J. , Jarzębski A.B.
FTIR Spectroscopic Study of Titanium-Containing Mesoporous Silicate Materials
Langmuir. 2005. V.21. N23. P.10545-10554. DOI: 10.1021/la0514516 WOS Scopus РИНЦ CAPlusCA OpenAlex

Поступила в редакцию:	2 июн. 2005 г.
Принята к публикации:	10 авг. 2005 г.
Опубликована online:	27 сент. 2005 г.
Опубликована в печати:	1 нояб. 2005 г.

Web of science:	WOS:000233129500051
Scopus:	2-s2.0-28044450410
РИНЦ:	13483437
Chemical Abstracts:	2005:1032311
Chemical Abstracts (print):	143:447510
OpenAlex:	W2040581625

БД	Цитирований
Web of science	42
Scopus	42
РИНЦ	42
OpenAlex	41