Copper-zirconia catalysts have shown high activities and selectivities for a NO-CO reaction at low temperature. Highly active Cu(L) species are produced by replacing the terminal OH groups of the ZrO2 surface and assigned to atomically dispersed Cu species. The deactivation of Cu(L) species took place in two steps; relatively rapid activity loss and subsequent slow deterioration. Treatments with 1% NO regenerated the deactivated Cu/ZrO2 at a much lower temperature than treatments with 5% O-2. The addition of Fe to Cu/ZrO2 was found to dramatically improve the catalytic performances; the activity and selectivity to N-2 at low temperature and catalytic stability. The mechanisms of reaction, deactivation, and regeneration are proposed.