Mesoporous SiO2‐Encapsulated Nano‐Co3O4 Catalyst for Efficient CO Oxidation

Abstract To meet the increasing demand for efficient and durable catalysts for exhaust aftertreatment system, a mesoporous SiO 2 ‐encapsulated nano‐Co 3 O 4 catalyst was synthesized, which possesses a unique pitaya‐like structure with high CO oxidation activity and thermal stability. Though the silica matrix is inert, the encapsulated Co 3 O 4 exhibits increased oxygen storage capacity, enhanced CO 2 desorption behavior and high lattice oxygen reactivity. Additionally, the SiO 2 ‐encapsulated Co 3 O 4 catalyst can be effectively regenerated rather than the supported Co 3 O 4 /SiO 2 and pure Co 3 O 4 . The kinetic results demonstrate that the L−H mechanism is followed over the pure Co 3 O 4 nanoparticles catalyst, while the CO oxidation over the silica‐supported Co 3 O 4 catalysts obey to both L−H and MVK mechanism. The encapsulation structure of the as‐prepared catalyst can effectively restrain the aggregation of Co 3 O 4 during high temperature operations and improves the utilization efficiency of cobalt resources, as well, which would be suitable for practical applications.