Large surface area ordered porous carbons via nanocasting zeolite 10X and high performance for hydrogen storage...

We report the preparation of ordered porous carbons for the first time via nanocasting zeolite 10X with an aim to evaluate their potential application for hydrogen storage. The synthesized carbons exhibit large Brunauer-Emmett-Teller surface areas in the 1300-3331 m(2)/g range and pore volumes up to 1.94 cm(3)/g with a pore size centered at 1.2 nm. The effects of different synthesis processes with pyrolysis temperature varied in the 600-800 °C range on the surface areas, and pore structures of carbons were explored. During the carbonization process, carbons derived from the liquid-gas two-step routes at around 700 °C are nongraphitic and retain the particle morphology of 10X zeolite, whereas the higher pyrolysis temperature results in some graphitic domains and hollow-shell morphologies. In contrast, carbons derived from the direct acetylene infiltration process have some incident nanoribbon or nanofiber morphologies. A considerable hydrogen storage capacity of 6.1 wt % at 77 K and 20 bar was attained for the carbon with the surface area up to 3331 m(2)/g, one of the top-ranked capacities ever observed for large surface area adsorbents, demonstrating their potential uses for compacting gaseous fuels of hydrogen. The hydrogen capacity is comparable to those of previously reported values on other kinds of carbon-based materials and highly dependent on the surface area and micropore volume of carbons related to the optimum pore size, therefore providing guidance for the further search of nanoporous materials for hydrogen storage.