Carbon monoxide hydrogenation over molybdenum carbide catalysts

Supported and unsupported molybdenum and molybdenum carbides have been studied as catalysts of CO-H-2 reactions at 570 K and atmospheric pressure. The initial turnover rates of these catalysts were comparable to those of the more active group VIII elements. However, all molybdenum-based catalysts showed a hydrocarbon product distribution different from those for typical group VIII metals. Furthermore, production of a large amount of CO2, (instead of water) and a high paraffin/olefin ratio reflected high activities of these catalysts for the water-gas shift reaction and hydrogenation, respectively. The high water-gas shift reaction activity allowed a CO-rich synthesis gas to be used efficiently over Mo-based catalysts. The CO-H-2 reactions appear to be structure insensitive on molybdenum carbide catalysts, since the rates were independent of particle size and crystal structure of unsupported catalysts and of metal loading of supported catalysts.