Carbon monoxide hydrogenation over molybdenum and tungsten carbides

• Published in: Applied catalysis. A, General General, 2003-09, Vol.251 (2), p.449-455
• Main Authors: Patterson, Patricia M, Das, Tapan K, Davis, Burtron H
• Format: Article
• Language: English
• Subjects: Catalysis; Catalytic reactions; Chemistry; Exact sciences and technology; Fischer–Tropsch synthesis; General and physical chemistry; Mo carbide; Theory of reactions, general kinetics. Catalysis. Nomenclature, chemical documentation, computer chemistry; W carbide; Water gas shift
• ISSN: 0926-860X; 1873-3875
• DOI: 10.1016/S0926-860X(03)00371-5

Hydrogenation of carbon monoxide was studied over the face centered cubic (fcc) phases of molybdenum and tungsten carbides. Moderately high surface area unsupported molybdenum and tungsten carbides (95 and 52 m 2 g −1, respectively) were prepared using a temperature programmed synthesis method. The starting oxides were first converted to a cubic nitride by reacting with ammonia, which are subsequently transformed to the carbide in a methane/hydrogen mixture. The presence of the face centered cubic structure was confirmed by X-ray diffraction. The catalysts were tested in a slurry continuously stirred tank reactor (CSTR) at P=2 MPa, in the temperature range 494–573 K and space velocities that varied from 2.5 to 15 S l h −1 g cat −1 . The production of large amounts of carbon dioxide instead of water in the case of molybdenum carbide indicates a high water gas shift activity. In both cases the main hydrocarbon product is methane.