Preparation of palladium-gold catalyst
View Patent ↗A method for preparing a palladium-gold catalyst containing a titania extrudate is disclosed. The titania extrudate is produced by using a carboxyalkyl cellulose and a hydroxyalkyl cellulose as extrusion aids. The titania extrudate has improved processibility and/or mechanical properties. After calcination, the extrudate is used as a carrier for the palladium-gold catalyst. The catalyst is useful in producing vinyl acetate by oxidizing ethylene with oxygen in the presence of acetic acid.
1. A process for preparing vinyl acetate, comprising the steps of:
(i) preparing a palladium-gold catalyst, wherein the preparing step further comprises the steps of:
(a) mixing titania, a carboxyalkyl cellulose, and a hydroxyalkyl cellulose to form a dough;
(b) extruding the dough to produce an extrudate;
(c) calcining the extrudate to produce a calcined extrudate;
(d) impregnating the calcined extrudate with a palladium compound and a gold compound to produce an impregnated extrudate; and,
(e) calcining the impregnated extrudate to produce the palladium-gold catalyst
(ii) reacting ethylene, oxygen, and acetic acid in the presence of the palladium-gold catalyst.
2. The process of claim 1 wherein the palladium-gold catalyst is further reduced.
3. The process of claim 2 wherein the palladium-gold catalyst is reduced by hydrogen.
4. The process of claim 3 wherein the reduced catalyst is further promoted by an activator.
5. The process of claim 1 wherein the titania is anatase.