Homogeneous introduction of CeOy into MnOx-based catalyst for oxidation of aromatic VOCs

Abstract

3MnOx-1CeOy (3Mn1Ce), a binary oxide with stoichiometric ratio of Mn/Ce=3, is synthesized via hydrolysis driving redox. Compared to MnO2, CeO2, Cop-3Mn1Ce and Mixed-3Mn1Ce, the 3Mn1Ce catalyst exhibits better catalytic activity for toluene oxidation, which could be ascribed to higher concentration of active lattice oxygen, and better low-temperature reducibility, as well as homogeneous dispersion. In the test of substrate applicability, 3Mn1Ce displays good performances in the removal of benzene, o-xylene and chlorobenzene at moderate temperature. The application of high WHSV of 240000mL/(g h) confirms the 3Mn1Ce catalyst still remains high efficiency to diminish toluene, giving the temperature at 280°C for complete mineralization. A set of experiments under simulated realistic exhaust conditions demonstrate that 3Mn1Ce is a robust catalyst with high activity to oxidize mixed aromatic VOCs (BTX and chlorobenzene), satisfied endurability to high humidity (above 10–20 vol.% water) and good tolerance to severe change of reaction temperature. With characterization of XRD and TPR, the high performance is related to the homogeneous introduction of Ce resulting in higher structural stability and reversible reducibility. Moreover, the inner principle for oxidation of VOCs is revealed by comprehension of kinetic study.