Identifying and Engineering Active Sites at the Surface of Porous Single-Crystalline Oxide Monoliths to Enhance Catalytic Activity and Stability

Abstract

Identifying and engineering active sites play a key role in many catalytic reactions. Herein, we create well-defined surface structures through the growth of porous single-crystalline Mn3O4 and Mn2O3 monoliths at centimeter scale and confine atomically dispersed Pt ions in the lattice at the twisted surface to construct isolated active sites. The activation of lattice oxygen linked to isolated Pt ions is much more effective than the lattice oxygen linked to Mn ions in local structures, leading to an approximately seven-to eightfold enhancement of surface oxygen exchange coefficients for catalytic CO oxidation. The active structures of PtO1.5 and PtO1.4 confined at the well-defined surfaces contribute to the efficient activation of lattice oxygen linked to Pt ions in local structures in addition to the chemisorption of CO in the oxidation reaction. We demonstrate the complete CO oxidation with air at 65 °C without degradation being observed even after continuous operation of 300 h.