Trimethylamine as a probe molecule to differentiate acid sites in Y-FAU zeolite: FTIR study

Francisca Romero Sarria; Vanessa Blasin-Aubé; Jacques Saussey; Olivier Marie; Marco Daturi

doi:10.1021/jp061729i

Trimethylamine as a probe molecule to differentiate acid sites in Y-FAU zeolite: FTIR study

J Phys Chem B. 2006 Jul 6;110(26):13130-7. doi: 10.1021/jp061729i.

Authors

Francisca Romero Sarria¹, Vanessa Blasin-Aubé, Jacques Saussey, Olivier Marie, Marco Daturi

Affiliation

¹ Laboratoire Catalyse & Spectrochimie, CNRS-ENSICAEN, 6 Bd du Maréchal Juin, 14050 Caen Cedex, France.

PMID: 16805624
DOI: 10.1021/jp061729i

Abstract

In heterogeneous catalysis acidity has a very important influence on activity and selectivity: correct determination of acidic properties is a base to improve industrial processes. The aim of this work was to study trimethylamine (TMA) as a probe molecule able to distinguish between the different Brønsted acid sites in zeolitic frameworks. Our work mainly focused on faujasite-type zeolites because the HY zeolite is one of the most used acidic catalysts in industrial processes. In this paper, typical IR bands assigned to TMA-protonated species (formed in supercages) are detected in the HY zeolite. TMA interacting by hydrogen bonding with the acid sites located in the sodalite units is also observed. The wavenumbers of some typical IR bands assigned to TMA-protonated species appear to depend on the acidic strength, and a complementary study with ZSM-5 and X-FAU samples confirms this proposition.