Title :

Influence of hierarchization on electron transfers in structured MFI-type zeolites

Author(s) :

Cremoux, Thomas [Auteur]
Laboratoire Avancé de Spectroscopie pour les Intéractions la Réactivité et l'Environnement - UMR 8516 [LASIRE]
Institut de chimie des milieux et matériaux de Poitiers [UMR 7285] [IC2MP [Poitiers]]
Batonneau-Gener, I. [Auteur]
Institut de chimie des milieux et matériaux de Poitiers [UMR 7285] [IC2MP [Poitiers]]
Moissette, Alain [Auteur]
Laboratoire Avancé de Spectroscopie pour les Intéractions la Réactivité et l'Environnement (LASIRE) - UMR 8516
Paillaud, J.-L. [Auteur]
Université de Haute-Alsace (UHA) Mulhouse - Colmar [Université de Haute-Alsace (UHA)]
Université de Strasbourg [UNISTRA]
Hureau, Matthieu [Auteur]
Laboratoire Avancé de Spectroscopie pour les Intéractions la Réactivité et l'Environnement (LASIRE) - UMR 8516
Ligner, E. [Auteur]
Université de Haute-Alsace (UHA) Mulhouse - Colmar [Université de Haute-Alsace (UHA)]
Morais, C. [Auteur]
Institut de chimie des milieux et matériaux de Poitiers [UMR 7285] [IC2MP [Poitiers]]
Laforge, S. [Auteur]
Institut de chimie des milieux et matériaux de Poitiers [UMR 7285] [IC2MP [Poitiers]]
Marichal, C. [Auteur]
Université de Haute-Alsace (UHA) Mulhouse - Colmar [Université de Haute-Alsace (UHA)]
Nouali, H. [Auteur]
Université de Haute-Alsace (UHA) Mulhouse - Colmar [Université de Haute-Alsace (UHA)]
Université de Strasbourg [UNISTRA]

Journal title :

Physical Chemistry Chemical Physics

Volume number :

20

Pages :

26903-26917

Publication date :

2018

HAL domain(s) :

Chimie/Chimie théorique et/ou physique

English abstract : [en]

H-ZSM-5 zeolite (Si/Al = 19.3) was hydrothermally synthesized. Alkaline and/or acid post-synthesis treatments were carried out to give rise to an interconnected mesoporous volume. The desilication treatment parameters have ...
Show more >H-ZSM-5 zeolite (Si/Al = 19.3) was hydrothermally synthesized. Alkaline and/or acid post-synthesis treatments were carried out to give rise to an interconnected mesoporous volume. The desilication treatment parameters have been tuned (temperature, organic base addition) to obtain a series of samples with increasing mesoporous volume and a constant number of acid sites. The physico-chemical properties of the resulting materials were fully characterized by many techniques (NMR, BET, PXRD, and pyridine thermal desorption followed by infrared spectroscopy). To assess the effect of post-treatments on sample reactivity, the charge separation processes between the zeolite framework and adsorbed trans-stilbene (t-St) molecule were investigated by UV-visible diffuse reflectance. The spectra obtained after t-St adsorption show clear differences depending on the applied post-treatments. It appears that the desilication treatments performed without acidic washing highly stabilize the radical cation resulting from the t-St spontaneous ionization. In contrast, by applying acidic washing after desilication, the ionization process becomes significantly weaker. The results show that the proportion of strong Lewis acid sites in the vicinity of Brønsted sites named Brønsted Strong Lewis Pairs (BSLP), are responsible for the amount of radical cations observed in the different samples. More precisely, it exists an optimal proportion of BSLP to achieve a high ionization rate. On the basis of the experimental results a mechanism for the formation of the t-St radical cation and the charge transfer complex (CTC) is proposed.Show less >

Language :

Anglais

Audience :

Internationale

Popular science :

Non

Collections :

• Laboratoire Avancé de Spectroscopie pour les Intéractions la Réactivité et l'Environnement (LASIRE) - UMR 8516

Research team(s) :

Photodynamique, confinement, solvatation (PCS)

Submission date :

2021-11-16T08:23:35Z
2024-02-14T07:36:11Z