Methane steam reforming on supported and non-supported molybdenum carbides

Alumina-supported and non-supported molybdenum carbides were prepared from trioxide of molybdenum for methane steam reforming. The transition metal carbides are formed in a process of carburization, substituting the oxygen by carbon atoms in the crystal lattice of these metals. The samples were carburized at 700degreesC, 800degreesC and 900degreesC. The characterization of solids was performed by elemental analysis, X-ray diffraction, N-2, adsorption and temperature-programmed surface reaction. Catalytic tests were carried through in a fixed-bed quartz micro-reactor and analyzed with on-line gas chromatography. All the catalysts show stability during the reaction. The most actives samples were those carburized at 700degreesC, both among the supported and non-supported catalysts. These solids had largest surface areas and the lowest free carbon deposition on the surface, leading to higher H-2 yields than catalysts treated at 800degreesC or 900degreesC. (C) 2004 Elsevier B.V. All rights reserved.