| 摘要 |
<p>A catalytically active material useful to prepare vinyl acetate monomer from ethylene, acetic acid, and an oxygen-containing gas under fluid bed conditions comprises a porous microspheroidal support containing catalytically active palladium crystallites finely dispersed within the support. This catalyst material does not require incorporation of gold to maintain activity and selectivity. A process to produce a vinyl acetate fluid bed catalyst in which catalytically active small palladium crystallites are finely dispersed within the support comprises dispersing selected metal species within the support which have an affinity to palladium to form very fine crystallites of palladium. The affinity metal species may be dispersed by impregnation onto a preformed microspheroidal support or may be intimately incorporated within the support before impregnation with a soluble palladium species.</p> |
