Unveiling the tailorable catalytic surface properties of ceria-promoted cobalt binary spinel catalysts for efficient N₂O direct decomposition

Spinel-type oxides based on transition metals are a specific class of catalysts that have recently been highly regarded as active sites for enhancing N₂O direct decomposition. The catalytic performance of Co_xCe_y binary spinel catalysts was compared to that of single Co and Ce oxide catalysts. The Co₂Ce₁ binary spinel catalyst exhibited superior N₂O decomposition performance, achieving over 95 % N₂O conversion at GHSV of 60,000 h⁻¹ and 300 °C. Physicochemical analysis revealed that the Co₂Ce₁ catalyst possessed the smallest particle size and the largest surface area, with Co occupying octahedral sites of Co spinel. Additionally, Ce weakened the Co−O bond and introduced abundant surface oxygen vacancies, basicity, and facilitated Co²⁺ and Ce³⁺ interactions on the catalyst surface. Furthermore, the number of Lewis acid sites emerged as a critical factor in N₂O decomposition. The Co₂Ce₁ catalyst demonstrated promising potential for efficient N₂O decomposition at lower temperatures.