Single atomic Pt confined into lattice defect sites for low-temperature catalytic oxidation of VOCs

Development of low-cost noble Pt-based catalyst with superior catalytic performance is a challenge to achieve its application in VOCs catalytic oxidation. Although the single atom provides a strategy to design and develop highly efficient heterogeneous catalysts that simultaneously maximizes the utilization of precious metal atoms, the stability of single atom catalysts is not satisfactory as a result of its high atomic surface energy. Here we construct a Pt1@CeO2 single atom catalyst (SAC) with excellent catalytic activity for benzene catalytic combustion (T90 = 212 °C) and low precious metal Pt loading, and even displaying an outstanding thermal stability and water resistance under the harsh conditions of 30,000 mL/g/h and 2000 ppm benzene. This Pt1@CeO2 catalyst was obtained by in situ domain limited encapsulation of Pt species in Ce-MOFs nanocages during the solvothermal reaction process. It is observed that lots of oxygen vacancies were created by the dislocation and phase transition of CeO2 to provide abundant sites for anchoring single atomic Pt, which can be localized and anchored firmly to oxygen vacancies, thus forming the highly stable Pt single atom. The atomically dispersed Pt is capable of improving the catalytic activity by forming Pt-O band. The good water resistance may be ascribed to the confined Pt single atom into oxygen vacancies of CeO2 support to form strong metal-support interaction (SMSI), and the PtOx nanoparticles would be easy to aggregate deactivation under water vapor conditions. It is a simple and universal strategy to prepare Pt SAC via the inherently confined space of MOFs nanocages formed by coordination of organic ligands and metal ions, which benefits from the functional modification of ethylene glycol in MOFs self-assembly reaction.