Carrier catalyst for the preparation of vinyl acetate from ethylene, acetic acid and oxygen in the gaseous phase

• US 4,370,261 A
• Filed: 03/13/1979
• Issued: 01/25/1983
• Est. Priority Date: 03/15/1978
• Status: Expired due to Term

• Current Assignee: Hoechst Aktiengesellschaft (Sanofi )
• Original Assignee: Hoechst Aktiengesellschaft (Sanofi )
• Inventors: Roscher, Gunter, Wunder, Friedrich, Heck, Gunther, Quadflieg, Therese
• Primary Examiner(s): DEES, CARL
• Application Number:
  US06/020,038
• Time in Patent Office: 1,414 Days
• Field of Search: 252/477 R, 252/460
• US Class Current: 502/328
• CPC Class Codes: B01J 2219/3023 Triangle
• CPC Class Codes: B01J 2219/30242 Star
• CPC Class Codes: B01J 2219/30273 Cross
• CPC Class Codes: B01J 23/58 with alkali- or alkaline earth metals
• CPC Class Codes: B01J 23/60 with zinc, cadmium or mercury
• CPC Class Codes: B01J 35/50 characterised by their shape or configuration
• CPC Class Codes: C07C 67/055 in the presence of platinum group metals or their compounds
• CPC Class Codes: C07C 69/01 Vinyl esters
• CPC Class Codes: C07C 69/15 Vinyl acetate

Abstract

The carriers contain common active components, namely noble metals of the 8th sub-group or compounds thereof, and as activators alkali metal compounds, alkaline earth metal compounds or cadmium compounds. The carriers, too, consist of common materials, such as silicic acid. A novel feature is to be seen in the shape of the carrier particles which are designed as rod sections having a star-shaped cross section (FIGS. 1 to 7) or as ribbed rods (FIG. 8). In relation to the apparent density and thus in relation to the amount of noble metal employed, a considerably higher space-time yield is reached than with carrier particles of a conventional shape.

Claims

1. An improved catalyst for the preparation of vinyl acetate in the gaseous phase from ethylene, acetic acid and oxygen or oxygen-containing gases of the type containing as an active component a noble metal of subgroup VIII optionally in admixture with gold and/or a compound thereof and an activator of an alkali metal compound and/or an alkaline earth metal compound and/or a cadmium compound wherein said active component is applied onto a carrer, wherein the improvement comprises a carrier consisting essentially of either ribbed rods or rods with a star-shaped cross section.

2. A catalyst as claimed in claim 1, wherein the cross section of the rods represent a 4- to 6-pointed star.

3. A catalyst as claimed in claims 1 or 2, wherein the carrier consists of silicic acid.