| 摘要 |
In the production of hydrogen by the catalytic decomposition of gaseous hydrocarbons such as methane, ethane or ethylene, the catalysts employed consist of mixtures or compounds of the oxides of the iron group (iron, cobalt or nickel) with acid-forming oxides of the A sub-group of the 4th, 5th or 6th groups of the periodic table having a melting-point above 800 DEG C.; the temperatures employed are in excess of this temperature. Examples of catalysts are nickel vanadate, titanate, or tungstate, cobalt uranate or vanadate, and iron vanadate or tungstate. Mixtures of NiO with V2O5, TiO2 or WO3, CoO with U3O8, and Fe2O3 with V2O5 or WO3 may also be employed, not necessarily in molecular proportions. The catalysts may be associated with carriers such as chamotte or porcelain. In an example of the process, methane is passed over granulated chamotte coated with nickel vanadate at 1000 DEG C.; the conversion is at first complete but falls off owing to the deposition of carbon at which point methane is replaced by air until the carbon is removed. The catalyst is prepared by evaporating a mixture of granulated chamotte and nickel nitrate and ammonium vanadate in solution. Specification 324,959, 325,207 and 327,374, [all in Class 90, Non-metallic elements], are referred to. |
