H/D reactivity and acidity of Bronsted acid sites of MWW zeolites: Comparison with MFI zeolite

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00216275%3A25310%2F19%3A39914312" target="_blank" >RIV/00216275:25310/19:39914312 - isvavai.cz</a>

Alternative codes found

RIV/61388955:_____/19:00517215 RIV/00216208:11310/19:10403681

Result on the web

<a href="https://www.sciencedirect.com/science/article/pii/S0926860X19300675?via%3Dihub" target="_blank" >https://www.sciencedirect.com/science/article/pii/S0926860X19300675?via%3Dihub</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1016/j.apcata.2019.02.024" target="_blank" >10.1016/j.apcata.2019.02.024</a>

Result language

angličtina

Original language name

H/D reactivity and acidity of Bronsted acid sites of MWW zeolites: Comparison with MFI zeolite

Original language description

Acid site strength in MWW and MFI zeolites was investigated by isotopic exchange reaction between deuterated hydroxyl groups of zeolites and ethane molecules. The course of the reaction was monitored by FT-IR spectroscopy through time changes of integral intensities of the Si(OD)Al Bronsted acid sites represented by absorption bands at 2644, 2655, and 2657 cm(-1) for MFI, MWW and MCM-36 zeolite, respectively. The rate of the reaction was described by pseudo first order kinetics and acid site strength was compared using rate constants characteristic of individual zeolites at constant temperature. The exchange reaction is significantly faster over MFI zeolite compared with MWW zeolites, suggesting a higher acid strength of Bronsted sites in MN zeolite than in MWW. In our previous study (Arean et al. Phys. Chem. Chem. Phys. 16 (2014) 10,129), we found notable discrepancy in the relation between OH group frequency shift induced by adsorption of weak base molecules like CO and N-2 and the change of adsorption enthalpy of these probe molecules for MWW zeolites, which calls into question the use of frequency shifts as a measure of acidity. Our reported results based on isotopic exchange reaction rate measurement correlate with the change of the probe molecules adsorption enthalpy involved in hydrogen bonding. Therefore, we believe that enthalpy change or H/D exchange activity measurement is more reliable method for assessment of acid strength than O-H frequency shift probed by a weak base adsorbed at a low temperature.

Czech name

—

Czech description

—

Type

J_imp - Article in a specialist periodical, which is included in the Web of Science database

CEP classification

—

OECD FORD branch

10403 - Physical chemistry

Project

<a href="/en/project/GBP106%2F12%2FG015" target="_blank" >GBP106/12/G015: Intelligent design of nanoporous adsorbents and catalysts</a><br>

Continuities

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

Publication year

2019

Confidentiality

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

Name of the periodical

Applied catalysis A: General

ISSN

0926-860X

e-ISSN

—

Volume of the periodical

575

Issue of the periodical within the volume

April

Country of publishing house

NL - THE KINGDOM OF THE NETHERLANDS

Number of pages

7

Pages from-to

180-186

UT code for WoS article

000462801700020

EID of the result in the Scopus database

2-s2.0-85062030879