New data on gas-phase radical reactions in the steam reforming of methane in the presence of catalysts: I. Nickel catalysts

Methane pyrolysis and steam reforming were studied over a series of nickel catalysts (Ni-Al2O3, Ni/MgO, and Ni/LiAlO2) under the same conditions (650- 750 degrees C, P-CH4 = 0.001-0.03 MPa). Unlike heterogeneous reaction of py rolysis, some of the steps of steam reforming of methane occur in the gas p hase. When gas-phase reactions were suppressed, the rate and activation ene rgy of steam reforming are close to the corresponding kinetic characteristi cs for pyrolysis. Hypothetically, the rate-limiting step of the process is the dissociative adsorption of methane on nickel in this case.