Development of ordered mesoporous ceria from metal-organic frameworks for efficient acetone oxidation: Morphologic and surficial advantages induced by surfactant-templated strategies.

Cerium oxide (CeO2) is one of the most effective catalysts for volatile organic compound (VOC) oxidation. However, the construction of ordered mesoporous CeO2 architectures through sustainable synthesis routes remains highly challenging. Metal-organic frameworks (MOFs) are promising sacrificial templates for the synthesis of oxides. Herein, we report a surfactant-regulated, alkali-metal-assisted aqueous strategy to construct ordered mesoporous CeO2 via UiO-66(Ce) templating. Pluronic was employed as a soft template, while inorganic bases (LiOH, NaOH, and KOH) were used to promote H2BDC deprotonation in water. The Li+, Na+, and K+ cations are believed to influence the self-assembly of UiO-66(Ce) framework (CeULi, CeUNa, and CeUK, respectively), leading to differences in the properties of the resulting particles. CeO2 derived from CeULi at low temperature, denoted as cCeULi, exhibited outstanding acetone conversion, reaching 90% at 207 °C. This is due to its mesoporous structure, the presence of Ce3+defects, and surface oxygen mobility. The cCeULi catalyst performed well over 10 cycles, averaging 87.9% efficiency over 25 h at 200 mg catalyst, 100 cc/min flow rate, and 600 ppm acetone. Also, cCeULi proved highly resistant to water vapor (5-10 vol%). In-situ DRIFTS analysis indicates that the acetone oxidation on cCeULi follows a Mars-van Krevelen mechanism involving lattice oxygen. Overall, the combination of morphological structure and surface chemical properties plays a key role in catalytic activity. This study is an important reference for the future development of ordered mesoporous CeO2 derived from MOFs.