Quantification of Lewis acid sites in 3D and 2D TS-1 zeolites: FTIR spectroscopic study

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00216208%3A11310%2F20%3A10419838" target="_blank" >RIV/00216208:11310/20:10419838 - isvavai.cz</a>

Výsledek na webu

<a href="https://verso.is.cuni.cz/pub/verso.fpl?fname=obd_publikace_handle&handle=tjCrfbkmMq" target="_blank" >https://verso.is.cuni.cz/pub/verso.fpl?fname=obd_publikace_handle&handle=tjCrfbkmMq</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1016/j.cattod.2019.10.011" target="_blank" >10.1016/j.cattod.2019.10.011</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Quantification of Lewis acid sites in 3D and 2D TS-1 zeolites: FTIR spectroscopic study

Popis výsledku v původním jazyce

Titanium silicalite 1 (TS-1) zeolite is an important selective oxidation catalyst. Recently prepared layered and pillared forms expanded the application of TS-1 to the catalytic oxidation of bulky molecules. Despite progress in designing and application of titanosilicate zeolites in catalysis, only qualitative information of their acidity is available. Herein, we report thorough characterization of acid sites in TS-1 zeolites of different morphologies (3D TS-1, layered 2D TS-1, 2D TS-1 pillared either with silica (TS-1-PISi) or silica-titania (TS-1-PITi)) using FTIR spectroscopy and probe molecules. FTIR of adsorbed pyridine was used for quantification of Ti-associated Lewis acid sites based on the integral intensity of nu(8a) absorption band ca. 1608 cm -1 and measured integrated molar extinction coefficient (epsilon(1608) (Ti-LAS) = 0.71 +/- 0.01 cm mu mol(-1)). Thermodesorption of pyridine monitored with FTIR showed that distribution of strength of Lewis acid sites is, to some extent, dependent on the way of Ti incorporation in the samples. TS-1-PITi, containing large fraction of external surface Ti(OH)(OSi)(3) species introduced post-synthesis, showed increased concentration of stronger Lewis acid centres. FTIR spectroscopy of TS-1 with pre-adsorbed quinoline and d(3)-acetonitrile probe confirmed enhanced relative concentration of external Lewis acid sites in all layered TS-1 materials (28-38%) vs. 3D TS-1 (2%).

Název v anglickém jazyce

Quantification of Lewis acid sites in 3D and 2D TS-1 zeolites: FTIR spectroscopic study

Popis výsledku anglicky

Titanium silicalite 1 (TS-1) zeolite is an important selective oxidation catalyst. Recently prepared layered and pillared forms expanded the application of TS-1 to the catalytic oxidation of bulky molecules. Despite progress in designing and application of titanosilicate zeolites in catalysis, only qualitative information of their acidity is available. Herein, we report thorough characterization of acid sites in TS-1 zeolites of different morphologies (3D TS-1, layered 2D TS-1, 2D TS-1 pillared either with silica (TS-1-PISi) or silica-titania (TS-1-PITi)) using FTIR spectroscopy and probe molecules. FTIR of adsorbed pyridine was used for quantification of Ti-associated Lewis acid sites based on the integral intensity of nu(8a) absorption band ca. 1608 cm -1 and measured integrated molar extinction coefficient (epsilon(1608) (Ti-LAS) = 0.71 +/- 0.01 cm mu mol(-1)). Thermodesorption of pyridine monitored with FTIR showed that distribution of strength of Lewis acid sites is, to some extent, dependent on the way of Ti incorporation in the samples. TS-1-PITi, containing large fraction of external surface Ti(OH)(OSi)(3) species introduced post-synthesis, showed increased concentration of stronger Lewis acid centres. FTIR spectroscopy of TS-1 with pre-adsorbed quinoline and d(3)-acetonitrile probe confirmed enhanced relative concentration of external Lewis acid sites in all layered TS-1 materials (28-38%) vs. 3D TS-1 (2%).

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10403 - Physical chemistry

Projekt

<a href="/cs/project/GX19-27551X" target="_blank" >GX19-27551X: ADORable katalyzátory</a><br>

Návaznosti

P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)

Rok uplatnění

2020

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Název periodika

Catalysis Today

ISSN

0920-5861

e-ISSN

—

Svazek periodika

345

Číslo periodika v rámci svazku

345

Stát vydavatele periodika

NL - Nizozemsko

Počet stran výsledku

8

Strana od-do

80-87

Kód UT WoS článku

000522039100010

EID výsledku v databázi Scopus

2-s2.0-85075479244