A three-way catalyst including a mixture of nickel and copper is provided for reducing carbon monoxide, hydrocarbon emissions, and nitrogen oxides from vehicle engine exhausts. The catalyst is impregnated onto a carrier substrate which is non-reactive with nickel and copper. When used in a vehicle exhaust gas treatment system, the nickel-copper catalyst provides improved efficiency in reducing CO, HC, and NOx emissions over the use of conventional three-way-catalysts and provides enhanced oxygen storage capacity (OSC) and water-gas-shift (WGS) functions.