Cu-exchanged zeolite catalysts with a chabazite structure containing selected concentrations of alkali ions or alkaline-earth ions and a lower concentration of (Cu) ions are described and a sequential process for making. Catalysts of the present invention reduce light-off temperatures providing enhanced low-temperature conversion of NOx gases. Catalysts of the present invention also exhibit high selectivity values compared to conventional NOx reduction catalysts.
STATEMENT REGARDING RIGHTS TO INVENTION MADE UNDER FEDERALLY-SPONSORED RESEARCH AND DEVELOPMENT
 This invention was made with Government support under Contract DE-ACO5-76RLO1830 awarded by the U.S. Department of Energy. The Government has certain rights in the invention.