Solid State Sciences 7 (2005) 861–867 www.elsevier.com/locate/ssscie Zeotile-2: A microporous analogue of MCM-48 Sebastien P.B. Kremer a , Christine E.A. Kirschhock a , Alexander Aerts a , Caroline A. Aerts a , Kristof J. Houthoofd a , Piet J. Grobet a , Pierre A. Jacobs a , Oleg I. Lebedev b , Gustaaf Van Tendeloo b , Johan A. Martens a,∗ a Centre for Surface Chemistry and Catalysis, Catholic University of Leuven, Kasteelpark Arenberg 23, B-3001 Leuven, Belgium b Centre for Electron Microscopy for Materials Science, University of Antwerp, Groenenborgerlaan 171, B-2020 Antwerpen, Belgium Received 1 October 2004; accepted 6 January 2005 Available online 19 April 2005 Abstract Ordered mesoporous materials with specific microporosity in the mesopore walls can be assembled by a secondary templating synthesis departing from a clear subcolloidal suspension dedicated to the tetrapropylammonium (TPA) mediated synthesis of colloidal Silicalite-1. A typical member of this material family is Zeotile-2. Zeotile-2 is mesostructurally similar to the cubic MCM-48 material with exceptional long-range order of the mesostructure. Zeotile-2 samples in which the TPA was either left or evacuated were prepared by leaching in boiling ethanolic acetic acid and calcination. The evacuation of the TPA gave rise to a substantial micropore volume revealed with nitrogen adsorption isotherms. The mesoporosity was independent of the presence of the TPA. Molecular separations of isooctane/octane mixtures illustrated the occurrence of molecular shape selectivity similar to MFI-type zeolites.  2005 Elsevier SAS. All rights reserved. Keywords: Zeolite; Microporous; Mesoporous; MCM-48; Zeotile-2; Synthesis; Nitrogen adsorption 1. Introduction The structuring of silica has been a lively research field for more than half a century. This important branch of the material science was boosted by the discovery of the syn- thetic zeolites, by Barrer et al. in the late 1940s [1,2]. Zeo- lites are silica materials containing specific pores and cav- ities with a diameter of less than 1 nanometer, capable of molecular sieving. A quest for larger pore sizes for appli- cations involving large molecules [3], culminated in the in- vention of the ordered mesoporous silica materials such as MCM-41 and -48 in 1992 by Kresge et al. [4,5] and SBA-15 in 1998 by Zhao et al. [6]. Today, asides the interest in mate- rials with new pore architectures, there is a growing demand for hierarchical silica materials having well-defined multi- ple porosity levels. In this context, there have been several efforts to create mesoporous materials having microporous * Corresponding author. Tel.: +32 16 32 16 10; Fax: +32 16 32 19 98. E-mail address: johan.martens@agr.kuleuven.ac.be (J.A. Martens). walls. Most of these studies are motivated by the appreciable increase of stability and acidity associated with the presence of zeolite bodies at the first structural level. In the recently discovered SBA-15 [6], the presence of microporosity was an unexpected side effect of the use of triblock copolymer as template for creating the mesopores. The polymer is partially embedded in the thick mesopore walls thus generating microporosity after calcination. The presence of microporosity in SBA-15 was revealed by sev- eral techniques including X-ray diffraction (XRD) reflec- tion intensity analysis [7], nitrogen adsorption isotherms and t -plot analysis [8–10], non-local density functional theory methods [11], characterization of carbon or platinum repli- cas [12–15], catalytic probing reactions [16], high-resolution electron microscopy (HREM) [17], and by the study of the intra-pore xenon condensation temperature using 129 Xe nu- clear magnetic resonance (NMR) [18,19]. Alternatively, the structure directing effect of organic template molecules for synthesizing zeolites can be ex- ploited for generating zeolite-like microporosity in meso- 1293-2558/$ – see front matter  2005 Elsevier SAS. All rights reserved. doi:10.1016/j.solidstatesciences.2005.01.021