(399f) Activation of Metal Sites Within Carbon Silica Composites for Enhanced Gas Adsorption

Carbon silica composites (CSCs) have been developed for their ability to target and adsorb a wide spectrum of light gases [1]. These materials take advantage of the specific interactions between the adsorbate and the adsorbent, which are dependent on the polarity of each [2,3].  CSCs are biphasic, with a nonpolar carbon phase that targets nonpolar gases and a polar silica phase that targets polar gases [2].  The silica phase of our CSCs is composed of mesoporous MCM-41, while the carbon phase is composed of carbonized furfuryl alcohol.  CSCs prove to be promising adsorbents because optimization of the phases of the composite during synthesis enhances adsorption capacities compared to the independent precursors [2].

Active metal sites have been shown to promote the chemisorption of gas molecules by inducing polarity and increasing the attraction between the adsorbate and the adsorbent in silica materials [4].  For this reason, metal-containing CSC materials have the potential to show enhanced adsorption properties for many types of gas molecules without compromising the structural characteristics of the base composite.  These materials are advantageous over single-phase adsorbents because they are biphasic and contain favorable attractions for both acidic and basic adsorbates. Such materials can be used for air purification applications to remove low concentrations of a variety of gases [1,2,4].

In this study, the CSC composite is modified by the consolidation of metal sites.  The [Metal]-CSCs have been further enhanced by acid/base treatments to increase the adsorption of target acidic and basic adsorbates.  Initial characterization and adsorption measurements for multiple series of [Metal]-CSCs (untreated/treated with acid/base) are presented.  All synthesized materials are structurally characterized using nitrogen isotherms, powder X-ray diffraction, and thermogravimetric analysis. 

[1] T. G. Glover, K. I. Dunne, R. J. Davis, M. D. LeVan, Microporous and Mesoporous Materials, 111, 1-11 (2008) 

[2] A. M. B. Furtado, Y. Wang, M. D. LeVan, Microporous and Mesoporous Materials, 165, 48-54 (2013)

[3] F. de Clippel, A. Harkiolakis, X. Ke, T. Vosch, G. V. Tendeloo, G. V. Baron, P. A. Jacobs, J. F. M. Denayer, B. F. Sels, Chemical Communications, 46, 928-930 (2010)

[4] A. M. B. Furtado, Y. Wang, T. G. Glover, M. D. LeVan, Microporous and Mesoporous Materials, 142, 730-739 (2011)