A METHOD FOR IMPROVING THE SELECTIVITY OF A CATALYST AND A PROCESS FOR THE EPOXIDATION OF AN OLEFIN

摘要

A method for improving the selectivity of a supported highly selective epoxidation catalyst comprising silver in a quantity of at most 0.19 g per m<2> surface area of the support, which method comprises - contacting the catalyst, or a precursor of the catalyst comprising the silver in cationic form, with a feed comprising oxygen at a catalyst temperature above 250 °C for a duration of up to 150 hours, and - subsequently decreasing the catalyst temperature to a value of at most 250 °C; and a process for the epoxidation of an olefin, which process comprises - contacting a supported highly selective epoxidation catalyst comprising silver in a quantity of at most 0.19 g per m<2> surface area of the support, or a precursor of the catalyst comprising the silver in cationic form, with a feed comprising oxygen at a catalyst temperature above 250 °C for a duration of up to 150 hours, and - subsequently decreasing the catalyst temperature to a value of at most 250 °C and contacting the catalyst with the feed comprising the olefin and oxygen.