Mixing small amounts of an inorganic halide, such as NaCl, to basic copper carbonate followed by calcination at a temperature sufficient to decompose the carbonate results in a significant improvement in resistance to reduction of the resulting copper oxide. The introduction of the halide can be also achieved during the precipitation of the carbonate precursor. These reduction resistant copper oxides can be in the form of composites with alumina and are especially useful for purification of gas or liquid streams containing hydrogen or other reducing agents. These reduction resistant copper oxides can function at near ambient temperatures.