Hydrogen uptake of carbon nanofiber under moderate temperature and low pressure

This paper describes the hydrogen uptake of carbon nanofibers at moderate temperature and low ambient pressure. The carbon nanofibers, having the herringbone structure, are synthesized with a catalyst support method in a hydrocarbon atmosphere. The obtained carbon nanofibers have a diameter of approximately 200-500 nm. The hydrogen uptake of the carbon nanofibers is investigated at the moderate temperatures from 303 to 873 K by using a thermogravimetry system. The 5.1 wt.% hydrogen uptake of the carbon nanofibers could be achieved in the KNO3 doping case. The influence of the ambient hydrogen pressure on the hydrogen uptake of carbon fibers is also investigated by changing the pressure from 0.05 to 1.0 MPa. The optimal ambient pressure was 0.1 MPa for the greatest hydrogen uptake. (C) 2003 Elsevier Science B.V. All rights reserved.