Preparation of mesoporous silica and carbon materials with multilength-scale pores and hydrogen sorption application

Abstract

A facile method was developed for the preparation of bimodal mesoporous siliceous materials with nanostructured pores in which a cationic organic template, n-hexadecy1trimethylammonium hydroxide, was employed as a base catalyst as well as a mesopore structure-directing agent during the slow condensation of tetraethoxysilane. It was possible to alter the pore orientations of smaller pores by adding neutral, auxiliary templates such, as Brij76 and P123. A series of bio-modal mesoporous carbons was also obtained from the bimodal mesoporous silica materials through a nanocasting process. The resulting bimodal mesoporous carbons exhibited decent hydrogen uptake values at 77 K. The maximum hydrogen uptake was 1.33 wt.-% for the sample having the narrowest pores, while keeping a relatively large pore volume. © 2009 Wiley-VCH Verlag GmbH & Co. KGaA.