Reaction of Graphite Filaments with Hydrogen above 2000°K

Abstract

The reaction rate of graphite and hydrogen has been measured between 2000° and 3400°K and pressures of 0.01 to 1.0 atm using a heated filament. At the lower temperatures and higher pressures, the reaction occurs on the surface and its rate is proportional to the hydrogen pressure and the K_D where K_D is the dissociation constant of hydrogen. At high temperature and low pressure, the reaction occurs in the vapor phase and is proportional to the sublimation rate of graphite. The sublimation temperature of graphite as a function of carbon to hydrogen ratio has been experimentally investigated at 0.1 atm and shown to agree with the estimated thermodynamic calculations.