| 摘要 |
Ammonia is synthesized by contacting hydrogen and nitrogen in the presence of a catalyst prepared by heating a transition metal oxide with an alkali metal at 450 DEG to 600 DEG C. in an inert atmosphere. The transition metal oxide is preferably an oxide of molybdenum, vanadium, chromium, cobalt or iron, but may be an oxide of scandium, yttrium, lanthanum, titanium, zirconium, hafnium, niobium, tantalum, tungsten, manganese, nickel, ruthenium, rhodium, platinum, palladium, osnium, or iridium. The alkali metal is present in an amount of at least 1%, preferably 5 to 300%, by weight of the oxide. The catalyst is prepared by mixing the oxide with the alkali metal and heating, or by impregnating a carrier, such as alumina, with a salt of the transition metal, converting it to the oxide, and distilling the alkali metal through the carrier while it is heated. The nitrogen and hydrogen are contacted with the catalyst at 200 DEG to 450 DEG C. at a pressure of 100 to 600 atmospheres for 0.02 to 100 seconds. In examples nitrogen and hydrogen are contacted with catalysts prepared from molybdenum trioxide, vanadium pentoxide, chromium trioxide, cobalt, oxide, iron oxide and sodium potassium and lithium. Specification 552,053 is referred to. |
