Effect of support and preparation on silver-based direct propylene epoxidation catalyst

Abstract

The effect of catalyst support and preparation method on silver-based catalysts for the direct vapor phase epoxidation of propylene to propylene oxide (PO) was studied. The shape of the CaCO3 support is critical for optimum activity and selectivity of the catalyst. Among the CaCO3 materials investigated as supports, the scalenohedral shape gives the best performance. A simplified method of catalyst preparation (referred to as “slurry method”) was developed. With this method, it is not necessary to dissolve Ag2O into a solution as in the conventional incipient wetness method for preparing silver-based catalysts for propylene and ethylene epoxidation. The key to the slurry method is the addition of a small amount of an effective organic compound, such as ethanolamine, during the formation of the slurry.