In this work, a highly active CeO₂ catalyst with hollow nanosphere morphology for low temperature NO_x storage was prepared by a surfactant-assisted solvothermal reaction. The physicochemical properties of ceria samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), N₂ adsorption–desorption, H₂-temperature programmed reduction (H₂-TPR), X-ray photoelectron spectroscopy (XPS) and in situ diffused reflectance infrared Fourier transform spectroscopy (DRIFTS). The as-prepared CeO₂ nanosphere possesses excellent NO oxidation capacity, smaller mesopores, better reducibility and more surface Ce³⁺ content. Compared with CeO₂ with nanorod and nanoparticle morphologies, CeO₂ nanosphere shows better intrinsic low temperature NO_x trapping performance, with a wide operating temperature window (150–300 °C), high NO_x adsorption capacity (NAC, 640–745 μmol/g) and high NO_x storage capacity (NSC, 250–350 μmol/g). Two reaction pathways are speculated for NO_x adsorption on CeO₂ nanosphere, including “nitrate route” and “nitrite route”. The thermally unstable surface nitrites formed on the CeO₂ nanosphere allow ceria to release more NO_x during the desorption process. The present work provides a new ceria morphology for NO_x traps, which may become a potential excellent NO_x storage material.

在这项工作中，通过表面活性剂辅助的溶剂热反应制备了具有中空纳米球形态的高活性 CeO ₂催化剂，用于低温储存 NO _{x 。}二氧化铈样品的理化性质通过X射线衍射(XRD)、扫描电子显微镜(SEM)、透射电子显微镜(TEM)、N ₂吸附-脱附、H ₂程序升温还原(H ₂ -TPR )、 X 射线光电子能谱 (XPS) 和原位漫反射红外傅里叶变换光谱 (DRIFTS)。所制备的 CeO ₂纳米球具有优异的NO氧化能力、更小的介孔、更好的还原性和更多的表面Ce ³⁺含量。与具有纳米棒和纳米颗粒形态的 CeO 2 相比，CeO _2纳米球表现出更好的内在低温 NO _x捕集性能，具有较宽的工作温度窗口（150-300 ℃），较高的 NO _x吸附容量（NAC，640-745 μmol/ g) 和高 NO _x存储容量 (NSC, 250–350 μmol/g)。_{推测在CeO 2}纳米球上吸附NO _x有两种反应途径，包括“硝酸盐途径”和“亚硝酸盐途径”。_{CeO 2}上形成的热不稳定表面亚硝酸盐纳米球允许二氧化铈在解吸过程中释放更多的_{NOx 。}目前的工作为NO _x捕集器提供了一种新的二氧化铈形态，可能成为一种潜在的优良NO _x储存材料。