A method is provided to manufacture a palladium-gold catalyst by separately impregnating and fixing the palladium and gold and reducing the fixed solids to free metal on a suitable support useful for vinyl acetate manufacture from ethylene and acetic acid.

Vinyl Acetate Catalyst Preparation Method

The present invention relates to a method of producing a catalyst or pre-catalyst suitable for assisting in the production of alkenyl alkanoates. The method includes contacting a modifier precursor to a support material to form a modified support material. One or more catalytic component precursors (palladium or gold) may be contacted to the modified support material. The atomic ratio of gold to palladium is preferably in the range of about 0.3 to about 0.90. The support materials with the catalytic component may then be reduced using a reducing environment. A composition for catalyzing the production of an alkenyl alkanoates including a modified support material with palladium and gold is also included within the invention. Catalysts of the present invention may be used to produce alkenyl alkanoates in general and vinyl acetate in particular and are useful to produce low EA/VA ratios while maintaining or improving CO2 selectivity.

Modified support materials for catalysts

This invention provides a process for producing improved catalysts for the production of alkenyl alkanoates by the reaction of an alkene, an alkanoic acid and an oxygen-containing gas. The catalysts contain palladium, gold and a potassium promoter and are characterized by a reduced sodium content which results in increased catalyst activity. The reduced sodium content is obtained by using essentially sodium-free starting materials in the process for producing the catalysts.

Production of alkenyl alkanoate catalysts

A process for the preparation of a fluid bed vinyl acetate (VAM) catalyst comprising impregnating a support comprising a mixture of substantially inert microspheroidal particles with a solution comprising a metal salt of Pd and M, wherein M comprises Ba, Cd, Au, La, Nb, Ce, Zn, Pb, Ca, Sr, Sb or mixtures thereof, reducing the metal salts to form a deposit of Pd and M on the support surface and impregnating the support with at least one alkali metal salt. At least 50% of the particles used for the microspheroidal support have a particle size below 105 microns.

Process for the preparation of fluid bed vinyl acetate catalyst

Disclosed are catalyst compositions comprising (i) one or more palladium group metals and/or compounds thereof; (ii) gold and/or compounds thereof; and (iii) optionally, an effective amount of one or more promoters selected from the group consisting of copper, nickel, cobalt, iron, manganese, lead, silver and compounds thereof. Preferably these catalyst compositions contain one or more promoters wherein the gram ratio of metal in the promoter to palladium group metal is up to about 0.4, wherein the catalysts are deposited on a support material and said support material is treated with one or more alkali metal bases and one or more alkali metal silicates prior to said deposition. Also described are processes for preparing ethylenically unsaturated esters comprising reacting in the vapor phase at least one olefinic compound with at least one carboxylic organic acid and molecular oxygen in the presence of an effective amount of the foregoing catalyst compositions.

Catalyst and process for using same for the preparation of unsaturated carboxylic acid esters

IMPROVEMENT IN A PROCESS FOR THE PRODUCTION OF VINYL ESTERS BY REACTING ETHYLENE, LOWER CARBOXYLIC ACIDS WITH 2 TO 4 CARBON ATOMS AND OXYGEN IN THE GAS PHASE AT ELEVATED TEMPERATURE AND NORMAL OR ELEVATED PRESSURE, IN THE PRESENCE OF SUPPORTED CATALYST CONSISTING ESSENTIALLY OF PALLADIUM, GOLD AND AN ALKALI METAL ACETATE ON A SILICIC ACID SUPPORT, WHICH IMPROVEMENT COMPRISES PREPARING THE CATALYST BY TREATING THE SUPPORT, SIMULTANEOUSLY OR SUCCESSIVELY OR IN COMBINATION WITH A SOLUTION A DND A SOLUTION B, THE SOLUTION A CONTAINING DISSOLVED SALTS OF PALLADIUM AND GOLD AND THE SOLUTION B CONTAINING COMPOUNDS WHICH ARE ABLE TO REACT ON THE CATALYST SUPPORT WITH THE NOBLE METAL SALTS OF THE SOLUTION A TO FORM WATER-IN-SOLUBLE NOBLE METAL COMPOUNDS WHICH ARE SUBSTANTIALLY FREE OF HALOGEN, SULPHUR AND NITROGEN, IMPREGNATING THE CATALYST SUPPORT WITH THE SOLUTIONS A AND B IR WITH THE COMBINED SOLUTION OF A AND B IN QUANITIES WHICH CORRESPOND TO FROM 1 TO 110% OF THE ABSORPTIVE CAPACITY OF THE CATALYST SUPPORT FOR THESE SOLUTIONS: SUBJECTING THE CATALYST SUPPORT IMPREGNATED WITH THE SOLUTIONS A AND B TO A TIME/ TEMPERATURE-TREATMENT WHICH IS SUCH THAT 95% AT LEAST OF THE IMTHE IMPREGNATED PALLADIUM AND 95% AT LEAST OF THE IMPREGNATED GOLD IS TRANSFORMED INTO WATER-INSOLUBLE NOBLE METAL COMPOUNDS, TREATING THE WATER-INSOLUBLE NOBLE COMPOUNDS WITH A REDUCING AGENT TO COVEY THESE COMPOUNDS SUBSTANTIALLY INTO THE CORRESPONDING NOBLE METALS AND REMOVING THE WATER-SOLUBLE COMPOUNDS WHICH ARE CONTAINED IN THE CATALYST BY WASHING, AND APPLYING AN ALKALI METAL COMPOUND BEFORE OR AFTER THE TREATMENT WITH THE REDUCIING AGENTS, THE ALKALI METAL COMPOUNDS CONSISTING OF ALKALI METAL CARBOXYLATES OR OF ALKALI METAL COMPOUNDS WHICH ARE WHOLLY OR IN PART TRANSFORMED INTO ALKALI METAL CARBOXYLATES UNDER THE REACTION CONDITIONS.

Process for the production of vinyl esters

Verfahren zur hydrierenden Behandlung von budadien- und n-Buten-1-haltigen C4-Kohlenwasserstoffen

Verfahren zur Herstellung von Vinylestern

Preparation of allyl acetate by reacting propylene, oxygen and acetic acid in presence of a catalyst. M5-.

Walter Kroenig

Papers

Process for the production of vinyl esters

Verfahren zur hydrierenden Behandlung von budadien- und n-Buten-1-haltigen C4-Kohlenwasserstoffen

Verfahren zur Herstellung von Vinylestern

Prepn of allyl acetate - by catalytic reacn. of propylene oxygen and acetic acid

Verfahren zur Herstellung von Oligomeren des Isobutens