Physical Hydrogen Storage on Nanotubes and Nanocarbon Materials

Abstract

The recent developments of carbonaceous material synthesis have resulted in several new forms of carbon such as carbon nanotubes and carbon nanofibers, and super-high surface area activated carbons nano-materials. There are speculations that these materials may have extraordinarily high hydrogen storage capacities. In this work, we examined the hydrogen gas adsorption capacities of these carbonaceous materials at room temperature, as well as at liquid nitrogen temperature, to elucidate the hydrogen storage potential of these materials. Experimental results indicated that none of these materials showed significant hydrogen storage capacities at room temperatures, and only super-high surface area activated carbon showed attractive gravimetric hydrogen storage at cryogenic temperature, of over 5.4% by weight at 77 K and at 300 psi hydrogen gas pressure. However, the nanocarbon materials produced from the activation of fullerene (AC-C60), and vacuum soot (AC-VAS) showed increased hydrogen adsorption capacity compared to the best commercial super-high surface area activated carbons. In addition, nanotubes showed enhanced storage capacity for their surface area. The challenge is to further modify nanotubes materials to achieve high surface area and consequently high hydrogen storage capacity.