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Carbon Molecular Sieves Prepared from Polymeric Precursors: Porous Structure and Hydrogen Adsorption Properties

2009; American Chemical Society; Volume: 48; Issue: 15 Linguagem: Inglês

10.1021/ie900091n

1520-5045

Ana Silvestre‐Albero, A.S.M. Wahby, Joaquín Silvestre‐Albero, F. Rodrı́guez-Reinoso, W.R. Betz,

Mesoporous Materials and Catalysis

The textural characterization of a series of carbon molecular sieves (CMS) prepared from different polymer precursors has been investigated using N2 adsorption at 77 K and CO2 adsorption at 273 K, together with immersion calorimetry into liquids of different molecular dimensions. Experimental results show that the carbon molecular sieves cover a wide range of porosity, from pure microporous CMS (pore diameter below 0.56 nm) to CMS combining larger micropores (above 0.7 nm) together with a certain proportion of mesoporosity. H2 adsorption measurements on these CMS at cryogenic temperature (77 K) and ambient pressure (0.1 MPa) show that the hydrogen adsorption capacity exhibits a linear correlation with the volume of narrow micropores (Vn). Furthermore, these results confirm experimentally the necessity of a tailored micropore size in order to achieve an optimum packing density of the adsorbed hydrogen molecules (micropore size around 0.6 nm).