• • Rh/CeO2-NR outperforms Rh/CeO2-NC and Rh/CeO2-NO under all tested conditions (inert, O2-containing, and H2O-containing), achieving higher N2O conversion at lower temperatures, which is critical for energy-efficient industrial abatement.
• • Rh/CeO2-NR exhibits abundant oxygen vacancies and intrinsic defect sites, facilitating O intermediate transfer and enhancing catalytic turnover, as confirmed by characterization.
• • The Rh0/Rhn+ ratio on Rh/CeO2-NR is optimal, promoting redox cycling between Rh species and reactants, which is essential for sustained catalytic activity.
• • The study demonstrates that support morphology engineering is a viable strategy to boost catalytic performance, potentially reducing precious metal loading requirements and operational costs in N2O emission control.