Advancements in cerium/titanium metal-organic frameworks: Unparalleled stability in CO oxidation

Abstract

Due to the excellent catalytic properties of Ce-based materials, the development of thermally stable metal-organic frameworks (MOFs) based on Ce-oxo clusters has attracted significant attention but remains challenging. In this work, we report the synthesis of an unreported Ce₄Ti₂-TMA (Ce^IV₄Ti^IV₂O₄(OH)₄(C(CH₃)₃COO)₁₂·3H₂O·3MeCN) cluster, which serves as an ideal source for the assembly of robust Ce/Ti-MOFs. Using this cluster, we constructed two isostructural MOFs, denoted as NU-3000 and NU-3001. Single-crystal X-ray diffraction analysis confirms these MOFs as mesoporous structures with 12-coordinated Ce₃Ti₃ nodes. Furthermore, structural analysis reveals a plane triangular node structure that likely contributes to the excellent thermal stability of these MOFs. Finally, both MOFs show catalytic activity toward high-temperature (250°C) CO oxidation and maintain significant porosity, emphasizing the thermal stability of these materials under practical catalytic conditions. The straightforward synthesis of thermally robust Ce/Ti-MOFs from the Ce₄Ti₂-TMA cluster will pave the way for future Ce/Ti-MOF-based catalyst development.