Performance of co-doped Mn-Ce catalysts supported on cordierite for low concentration chlorobenzene oxidation

The catalytic activity for low concentration chlorobenzene oxidation was measured with Mn-Ce/cordierite and Mn-Co-Ce/cordierite catalysts with different mole ratios, which were prepared by a sol-gel method and characterized using XRD, BET, SEM Raman, H₂-TPR and XPS. The results demonstrated that part of the manganese and cobalt could be incorporated into the lattice of CeO₂ to form a solid solution phase. Among all of the catalysts synthesized, Mn₈Co₁Ce₁/cordierite presented the best activity and stability. When the concentration of chlorobenzene was 500 ppm, and the GHSV was 15000 h⁻¹, the complete combustion temperature (T_90%) of chlorobenzene was 325 °C. In addition, there was almost no change in the conversion of chlorobenzene during the long-term reaction at 350 °C. These results were primarily attributed to the synergistic effect of ceria, manganese and cobalt, which can promote the formation of more lattice defects, more oxygen vacancies and smaller crystallite sizes.