Synthesis and characterization of MCM-41-supported Ba 2 SiO 4 base catalyst Quanchang Li a , Suzanne E. Brown a , Linda J. Broadbelt a, * , Jian-Guo Zheng b , N.Q. Wu c a Department of Chemical Engineering, Center for Catalysis and Surface Science, Northwestern University, 2145 Sheridan Road, Evanston, IL 60208-3120, USA b Department of Materials Science and Engineering, Electron Probe Instrumentation Center, Northwestern University, Evanston, IL 60208, USA c Department of Chemistry, Keck Interdisciplinary Surface Science Center, Northwestern University, Evanston, IL 60208, USA Received 26 September 2002; received in revised form 20 January 2003; accepted 23 January 2003 Abstract A novel MCM-41-supported base catalyst, Ba-MCM-41, was synthesized with a modified impregnation method. Ba 2 SiO 4 was synthesized on the MCM-41 pore wall as confirmed by characterization using X-ray diffraction, X-ray photoelectron spectroscopy, X-ray fluorescence, N 2 adsorption, 29 SiMASNMRandtransmissionelectronmicroscopy. It was also demonstrated that a highly ordered Ba-MCM-41 catalyst with high barium loading (4.1–25.2 wt.%) and dispersion was obtained using this method. The basicity of the catalyst, which was characterized according to the binding energy of O1s, was increased with increasing amounts of barium in the catalyst. Ó 2003 Elsevier Science Inc. All rights reserved. Keywords: Barium; MCM-41; Barium silicate; Impregnation 1. Introduction The discovery [1,2] of MCM-41 mesoporous molecular sieves has sparked much research into developing new materials with uniform pore size and shape that have very high surface area and adsorption capacity. The development of such ma- terials is of great importance in many areas of modern science and technology [3–6]. These ma- terials are best appreciated in systems where mo- lecular recognition is needed, e.g., shape-selective catalysis, selective adsorption and separation pro- cesses, chemical sensors, and nanotechnology. Or- dered mesoporous oxides of the MCM-41 type have been used and evaluated with respect to their catalytic properties as supports, mainly for metal particles or molecular catalysts. However, they might also be useful, with possibly even broader applications,forthepreparationofsupportedbase metal oxides that are important in many catalytic reactions [7]. Acommonmethodforpreparingsupportedbase metal oxides is impregnation, where a porous sup- port is repeatedly dipped into a solution contain- ingadesiredcatalyticagent.Itisoftendesirableto * Corresponding author. Tel.: +1-847-491-5351/7398; fax: +1-847-491-3728. E-mail address: broadbelt@northwestern.edu (L.J. Broad- belt). 1387-1811/03/$ - see front matter Ó 2003 Elsevier Science Inc. All rights reserved. doi:10.1016/S1387-1811(03)00290-7 www.elsevier.com/locate/micromeso Microporous and Mesoporous Materials 59 (2003) 105–111