Abstract: A non-precious metal three-way catalyst which reduces hydrocarbon, carbon monoxide, and nitrogen oxide from internal combustion engine exhaust and industrial emissions, with a conversion capability comparable to the conversion efficiencies of current precious metal catalysts, and with superior NO.sub.x conversion characteristics, and durable when operated under prolonged high temperature conditions. The light-off temperature is close to the light-off temperature of convertional precious metal catalysts. The active catalytic components in this catalyst are a mixture of rare-earth metal and non-noble metal oxides.