The performance of a NOx storage-reduction (NSR) catalyst is strongly dependent on the relative stabilities of nitrates and sulfates on the catalyst surface. This effort studies the effects of introducing 5 mol% La, Ca, and K-dopants into a BaO phase of a model Pt/Ba/Al2O3 NSR catalyst. The dopants were chosen with a range of properties to affect the BaO lattice spacing and/or the number of oxygen vacancies. The resulting changes in the storage material, in turn, impact the stability of stored nitrates and sulfates, as measured by NOx conversions and desulfation temperatures. The Ca- and La-doped material shows equivalent or better NOx reduction performance between 200 and 400 degrees C, while the K-doped NSR catalyst showed significant decreases in performance at 200 degrees C but maintained the high performance at 300 and 400 degrees C. Following the performance measurements, the samples are then sulfated to 5.5 mg S/gcat and desulfated to 1000 degrees C. All NSR catalysts generally show similar desulfation behavior, but in determining the temperature of 20% sulfur removal (T-20%), it is shown that the Ca + Ba sample has a 25 degrees C lower T-20% than both the Ba-only and La + Ba samples, while K + Ba is 70 degrees C higher. Additional Ca-based samples were than prepared at the 10, 20 and 100 mol% levels. The higher Ca-doped materials show similar NOx reduction performance, but the 5% Ca + Ba sample maintains the lowest T-20%. Interestingly, the Ca-only sample has a T-20% that is 60 degrees C higher than the Ba-only NSR catalyst, which indicates that the introduction of 5% Ca into the Ba-lattice has a synergistic effect in lowering the desulfation temperature. (C) 2010 Elsevier B.V. All rights reserved.