DeNOx activity of 0.5% Pd–30% La0.5Ba0.5CoO3/Al2O3 formulation is analysed in single-NSR and combined NSR–SCR systems, using response surface methodology (RSM). Operational maps are built for any combination of reaction temperature in the NSR and SCR beds and H2 concentration. A 4% Cu/SAPO-34 is used as the SCR catalyst. Results for single-NSR allows tuning operational conditions in coupled NSR-SCR technology to maximize NOx-to-N2 conversion, with minimum NH3 and N2O productions. Control of H2 concentration and temperature in the NSR system allows generating the stoichiometric amount of NH3 to eliminate NOx slipping. The tuned coupled NSR–SCR system achieves high N2 yield under wide operational range (T=175–425 °C; CH2=2–4%). Specifically, N2 yield reaches 92% when NSR and SCR catalysts work at 300 °C and 3% H2 is injected, with NH3 slip and N2O production nearly zero. This provides a promising alternative for NOx removal in diesel aftertreatment systems.