FIELD: organic synthesis catalyst. SUBSTANCE: carrier is characterized by sodium solubilization rate determined from amount of sodium released on immersion for 5 min of carrier in boiling water, at weight ratio of boiling water to carrier 3:1, no more than 5 ppm based on the total weight of carrier. Catalyst preparation process is characterized by that required sodium solubilization rate is achieved through a method effective for transferring ionizable particles located on carrier surface into ionic state and removing then at least part of these particles or for transferring ionizable particles into insoluble state, or for transferring these particles into steady state. Catalyst contains above-defined carrier, silver, and optionally promoter. Catalyst is prepared by impregnating it with solution wherein hydrogen ion activity is lowered by adding base. In addition, process of catalytic epoxidation of alkene with oxygen-containing gas is claimed. Claimed carriers with controlled solubilization rate ensure preparation of improved catalysts. EFFECT: increased activity and selectivity of catalyst. 9 cl, 3 tbl, 12 ex
