Abstract:
A core-shell structured Pd-Co
3O
4@SiO
2 catalyst was prepared by a simple self-assemble method and used in lean methane combustion. The results of catalytic tests indicate that the core-shell Pd-Co
3O
4@SiO
2 catalyst exhibits high activity in lean methane combustion and superior stability at high temperature. The results of TEM, XRD, and H
2-TPR characterization suggest that the high activity of Pd-Co
3O
4@SiO
2 is mainly ascribed to the strong interaction between CoO
x and PdO species inside the SiO
2 shell. Meanwhile, as the active Pd and CoO
x species in Pd-Co
3O
4@SiO
2 are enshielded in the core-shell structure, which is effective to protect the active phase from sintering at high temperature, the core-shell structured Pd-Co
3O
4@SiO
2 catalyst is thus far superior in thermal stability against high temperature to the supported Pd/Co
3O
4@SiO
2 and Pd/Co
3O
4-SiO
2 catalysts.