Metal organic framework for the fabrication of mutually interacted PtCeO2C ternary nanostructure: advanced electrocatalyst for oxygen reduction reaction

Metal nanoclusters have attracted increasing attentions due to their extremely high catalytic activities. However, how to keep their structural and catalytic stabilities is still a challenge, especially in electrocatalysis . Herein, a novel mutual-interacted Pt CeO 2 C ternary nanostructure was designed and fabricated from Ce-based metal organic framework (Ce-MOF). In this unique nanostructure, through a calcination process, abundant tiny CeO 2 nanoclusters (∼2 nm) can be produced from the Ce-MOF itself and they are uniformly inserted in the MOF-derived porous carbon matrix. Meanwhile, the following deposited surfactant-free Pt nanoclusters (∼2 nm) contact well with both carbon and CeO 2 nanoclusters. The electrocatalytic activity of the Pt CeO 2 C ternary nanostructure for the oxygen reduction reaction (ORR) was investigated. With such ternary structure, the interacted CeO 2 and Pt nanoclusters showed high stability. Moreover, the CeO 2 can modify the electronic density of Pt and enhance the interaction between Pt and carbon at the Pt CeO 2 interface. Meanwhile, with the mutual interaction, the corrosion resistance of carbon can be improved at the CeO 2 C interface, and the conductivity of the catalyst can be improved with the carbon framework. With these structure advantages, the Ce-MOF-derived catalyst exhibited higher electrocatalytic performance than commercial Pt C for ORR with more positive half-wave potential and higher limiting diffusion current density. The origin of the enhanced ORR performance was further disclosed by X-ray absorption fine spectroscopy (XAFS) characterization.