摘要:
A method for pretreatment of a palladium-gold catalyst useful in the synthesis of vinyl acetate. A virgin catalyst, following reduction to the metallic palladium and gold, is first heated at elevated temperatures in the presence of an oxidizing agent such as air. The oxidizing agent is withdrawn and an inert gas such as nitrogen is introduced. The catalyst is heated against at a temperature up to 500.degree. C. in the presence of a reducing agent such as hydrogen or ethylene. Improvement in selectivity and yield are obtained.
摘要:
A method for pretreatment of a palladium-gold catalyst useful in the synthesis of vinyl acetate. A virgin catalyst, following reduction to the metallic palladium and gold, is first heated at elevated temperatures in the presence of an oxidizing agent such as air. The oxidizing agent is withdrawn and an inert gas such as nitrogen is introduced. The catalyst is heated again at a temperature up to 500.degree. C. in the presence of a reducing agent such as hydrogen or ethylene. Improvements in selectivity and yield are obtained.
摘要:
Crystalline Group VIII metal aluminosilicate compositions which are prepared by exchanging or impregnating a Group VIII metal onto an aluminosilicate. Conversion of methanol in the presence of a hydrogen cofeed to low molecular hydrocarbons employing these aluminosilicates as catalysts is also disclosed.
摘要:
A process for the production of secondary-butyl perfluoroester is provided by reacting ethylene with a perfluorocarboxylic acid in the presence of oxygen.
摘要:
A process is disclosed for preparing a cyclic ether which comprises cyclodehydrating a polyhydroxy compound of the general formulaHOR.sup.1 HC--R.sup.2 --CHR.sup.3 OHin which R.sup.1 and R.sup.3, each of which is the same or different, is hydrogen or a lower aliphatic, cycloaliphatic or aryl group and R.sup.2 is a divalent aliphatic group of 1 to 10 carbon atoms containing 0, 1 or 2 etheric oxygen atoms or 0, 1 or 2 secondary or tertiary amine nitrogen atoms and 0, 1 or more lower aliphatic, cycloaliphatic and/or aryl groups containing 0 or 1 hydroxyl groups at elevated temperatures in the presence of a catalytically effective amount of a Group VIII metal catalyst or a Group VIII metal-containing material to provide a cyclic ether of the general formula ##STR1## in which R.sup.1, R.sup.2 and R.sup.3 are as defined above. The process is especially useful for preparing the commercially important cyclic ethers tetrahydrofuran and 1,4-dioxane which are derived from 1,4-butanediol and ethylene glycol and/or diethylene glycol, respectively.
摘要:
A process is described for the preparation of aromatic aldehydes such as benzaldehyde and substituted benzaldehydes by the liquid phase oxidation of toluene or substituted toluenes in the presence of a catalyst comprising phosphoric acid and a catalytically effective amount of palladium metal, and a sulfur, phosphorus or nitrogen modifier.
摘要:
A process is described for the preparation of aryl esters such as benzyl acetate by reacting an aryl alkyl compound such as toluene with a carboxylic acid such as acetic acid and oxygen in the presence of a catalytically effective amount of a catalyst comprising palladium metal, gold metal and a metal of Group VA of the Periodic Table of the Elements such as bismuth.
摘要:
Ethylene and oxygen are reacted in the presence of steam in the vapor phase within the temperature range of from about 150.degree. C. to about 250.degree. C. in contact with a catalytically effective amount of palladium metal on a zinc oxide support in the presence of a sulfur modifier to provide mixtures of acetic acid and vinyl acetate.
摘要:
A process for the selective production of acetic acid from ethylene with co-production in minor amounts of carbon oxides, by reaction of ethylene and oxygen in the presence of water and a catalyst composition contaning a catalytically effective amount of palladium metal and a sulfur modifier.