| 摘要 |
Organic acetates are prepared by reacting an olefine or alkyl benzene with oxygen and acetic acid in the presence of a palladium metal catalyst supported upon aluminium spinel which may contain aluminium oxide. Ethylene, propylene and iso-butylene, and toluene and xylene are mentioned and the support may be impregnated with palladium salt followed by reduction with hydrazine hydrate or hydrogen at high temperatures. Alkali or alkaline earth metal acetates, e.g. sodium, potassium, magnesium or calcium, may also be present. The spinel support is prepared from metals such as lithium, beryllium, magnesium, zinc, and bivalent manganese, iron, cobalt and nickel. Examples describe the preparation of vinyl acetate, allyl acetate, benzyl acetate and benzal diacetate.ALSO:Palladium metal catalysts deposited on a support consisting partly or completely of aluminium spinel which may contain aluminium oxide, are used in the preparation of organic acetates by reacting an olefine or alkyl benzene at elevated temperature with oxygen and acetic acid. The catalyst support is prepared by adding the spinel-forming metals e.g. lithium, beryllium, magnesium, zinc and in the bivalent form, manganese, iron cobalt and nickel, as salts or hydroxides to the aluminium oxide, drying, converting to oxide at from 250-650 DEG C, and finally heating at 900 to 1200 DEG C to form the spinel. The aluminium oxide may be in piece form, or fine-grained and in a modification metal aluminates may be precipitated from aqueous aluminium salt solutions by adding salts of spinel forming metals and heat treating the product. In a further method the aluminium oxide or hydroxide is mixed with spinel-forming metal oxides or hydroxides, ground, shaped and heated to form the spinels. The palladium is deposited e.g. 0.1 to 10.1 by weight by impregnation with a salt solution followed by reduction with hydrozine hydrate, or hydrogen. Alkali or alkaline earth metal acetates e.g. potassium, sodium magnesium or calcium may also be included and the process may use fixed or moving bed catalyses. |
