The Energetics of Surfactant‐Templating of Zeolites. (7th June 2018)

• Record Type: Journal Article
• Authors: Linares, Noemi; Jardim, Erika O.; Sachse, Alexander; Serrano, Elena; García‐Martínez, Javier
• Is Part Of: Angewandte Chemie. Volume 130:Number 28(2018)
• Page Start: 8860
• Page End: 8864
• Publication Date: 2018-06-07
• Subjects: Effektive Aktivierungsenergie -- Mesoporöse Zeolithe -- Reaktionskinetik -- Synchrotron-Charakterisierung -- Tensidtemplate; Chemistry -- Periodicals; 540
• DOI: 10.1002/ange.201803759
• Languages: English
• ISSNs: 0044-8249

Abstract

Abstract: Mesoporosity can be conveniently introduced into zeolites by treating them in basic surfactant solutions. The apparent activation energy involved in the formation of mesopores in USY by surfactant‐templating was determined using a combination of in situ synchrotron X‐ray diffraction and ex situ gas adsorption. Additionally, techniques such as pH measurement and thermogravimetry/differential thermal analysis were employed to determine OH − evolution and cetyltrimethylammonium ion (CTA + ) uptake during the development of mesoporosity, thereby providing information about the different steps involved. The combination of both in situ and ex situ techniques has allowed determination of the apparent activation energies of the different processes involved in the mesostructuring of USY zeolites for the first time. Apparent activation energies are of the same order of magnitude (30–65 kJ mol −1 ) as those involved in the crystallization of zeolites. Hence, important mechanistic insight into the surfactant‐templating method was obtained. Abstract : Mit wenig Energie zu großen Poren : Die Mesostrukturierung von Zeolithen mit Tensiden gelingt unter den typischen Zeit‐ und Temperaturbedingungen von Zeolithsynthesen. Eine systematische Studie der Mesoporenbildung in USY‐Zeolith bei unterschiedlichen Temperaturen mittels In‐situ‐ und Ex‐situ‐Techniken liefert die Kinetiken des Bildungsprozesses. Die effektiven Aktivierungsenergien sind ähnlich (30–65 kJ mol −1 ) wie für die Kristallisation von Zeolithen.