ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Montmorillonite intercalated with SiO₂, SiO₂-Al₂O₃ or SiO₂-TiO₂ pillars by surfactant-directed method as catalytic supports for DeNOx process

Lucjan Chmielarz, Andrzej Kowalczyk, Magdalena Wojciechowska, Paweł Boroń, Barbara Dudek, and Marek Michalik

Faculty of Chemistry, Jagiellonian University, Ingardena 3, 30-060, Krakow, Poland

E-mail: chmielar@chemia.uj.edu.pl

Abstract: The intercalation of natural montmorillonite with SiO₂, SiO₂-Al₂O₃ or SiO₂-TiO₂ pillars by the surfactant-directed method resulted in the formation of high surface area porous materials; these were tested as catalytic supports for the process of selective catalytic reduction of NO (DeNOx). The incorporation of titanium or aluminium into the structure of the silica pillars significantly increased the surface acidity of the clay samples. Iron and copper were deposited onto the surface of the pillared clays mainly in the form of monomeric isolated cations and oligomeric metal oxide species. The contribution of the latter species was higher in the clay intercalated with SiO₂-TiO₂ pillars than in the samples modified with SiO₂ and SiO₂-Al₂O₃ pillars. The pillared clay-based catalysts were active in the DeNOx process but, in this group, the best results were obtained for the clay intercalated with SiO₂-TiO₂ pillars and doped with iron and copper. The catalytic performance of the samples is discussed in respect of their surface acidity and active forms of transition metal species deposited.

Keywords: montmorillonite – intercalation – surfactant-directed method – porous clay heterostructures (PCHs) – selective catalytic reduction (DeNOx) – nitric oxide

Full paper is available at www.springerlink.com.

DOI: 10.2478/s11696-013-0463-0

Chemical Papers 68 (9) 1219–1227 (2014)