A process for producing propylene from a C4 feed containing 2-butene includes contacting said feed with ethylene in a metathesis reaction zone containing a metathesis catalyst under metathesis reaction conditions to provide an effluent including propylene, said metathesis catalyst consisting essentially of a transition metal or oxide thereof supported on a high purity silica support possessing less than about 150 ppm magnesium, less than about 900 ppm calcium, less than about 900 ppm sodium, less than about 200 ppm aluminum, and less than about 40 ppm iron.