Synthesis and High Hydrogen Storage Capacity of Zeolite-Like Carbons Nanocast Using As-Synthesized Zeolite Templates

Abstract

As-synthesized zeolite β has been successfully used as a template for the preparation, via chemical vapor deposition, of well ordered zeolite-like carbon materials. The carbon materials have high surface area (1720−2535 m2/g) and high pore volume (1.09−1.56 cm3 g-1) and exhibit some zeolite-like structural ordering replicated from the zeolite template. Carbon materials prepared at 800 and 850 °C are nongraphitic and retain the particle morphology of the zeolite templates. Carbon prepared at 900 °C contains some graphitic domains (as indicated by XRD patterns) and irregular particles that are dissimilar to the zeolite template particles. We observed hydrogen uptake of up to 5.3 wt % at −196 °C and 20 bar, and 2.3 wt % at 1 bar, for the carbon materials. The hydrogen uptake is dependent on the surface area of the carbons. The use of as-synthesized (rather than calcined) zeolite β significantly improves the carbon yield and reduces the number of steps in the preparation of the templated carbons.