A low temperature method for reducing and purifying refractory metals, metal compounds, and semi-metals using a catalyst. Using this invention, TiO.sub.2 can be reduced directly to Ti metal at room temperature. The catalyst is an ion in an electrolyte that catalyzes the rate of the reduction of a compound MX to M, wherein M is a metal or a semi-metal; MX is a metal compound, a semi-metal compound, or a metal or semi-metal dissolved as an impurity in M; and X is an element chemically combined with or dissolved in M.