The invention is directed to a catalyst for the epoxidation of an olefin to an olefin oxide, the catalyst comprising a support having at least two pore size distributions, each pore size distribution possessing a different mean pore size and a different pore size of maximum concentration, the catalyst further comprising a catalytically effective amount of silver, a promoting amount of rhenium, and a promoting amount of one or more alkali metals, wherein the at least two pore size distributions are within a pore size range of about 0.01 μm to about 50 μm. The invention is also directed to a process for the oxidation of an olefin to an olefin oxide using the above-described catalyst.