Characterization of Microporous Titanosilicate ETS-10 by Infrared Spectroscopy with Methane as a Probe Molecule for Basic Sites

In situ infrared spectroscopy with probe molecules is a useful technique for the characterization of solid surfaces. The selection of an appropriate probe molecule is critical for this technique. In this study, the usefulness of methane as a probe for basic sites in microporous titanosilicate ETS-10 is demonstrated. With the help of carbon monoxide as a probe for cationic sites, some absorption bands of methane were assigned as methane molecules adsorbed on basic sites. The frequencies of these bands indicated that the strengths of the basic sites of Na-ETS-10 and Cs-ETS-10 are in the same degree with those of MgO, NaY, and CsY. On the basis of the spectroscopic results, the locations of the adsorption sites in the crystal framework are also discussed.