Na-Doped Cobalt-Based γ-Al 2 O 3 Catalysts with Enhanced Electronic Modulation for High NO Selectivity in N 2 O Decomposition

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Nitrous oxide (N 2 O), recognized as both a potent greenhouse gas and an ozone-depleting substance, has become a focal point for environmental research, driving the urgent need for efficient decomposition strategies. This study innovatively introduces an advanced catalytic system for direct N 2 O decomposition, which selectively transforms N 2 O into nitric oxide (NO) at elevated temperatures ranging from 600 to 900 °C. This conversion provides a valuable feedstock for subsequent nitric acid synthesis, thereby creating a novel pathway that seamlessly integrates environmental protection with economic benefits for N 2 O mitigation. Cobalt-based catalysts supported on γ-Al 2 O 3 were meticulously prepared using the wet-impregnation method and further optimized through the introduction of Fe and Na modifiers. The experimental results demonstrate that across the 600–900 °C temperature range, all prepared catalysts achieved complete conversion of N 2 O. Among them, the Na-doped modified catalyst exhibited the most outstanding performance, attaining a remarkable NO selectivity of 4.28% at 900 °C. The incorporation of Na triggered electron-transfer processes, effectively weakening the N–O bond within N 2 O molecules and facilitating the formation of oxygen species adsorbed on the active sites of the catalyst (*O). This modification also significantly altered the adsorption properties on the catalyst surface, thereby regulating the residence time of key reaction intermediates and ultimately directing the N 2 O conversion pathway toward NO formation.