Facile preparation of hollow MnOx-CeO2 composites with low Ce content and their catalytic performance in NO oxidation

The Mn-Ce mixed oxides are frequently used for catalytic oxidation of NO. However, to achieve better performance, a large amount of Ce element is usually engaged in the preparation, in spite of its low abundance and high cost. Herein, a facile sovothermal method was presented to prepare hollow MnOx-CeO2 composites. The structural and physiochemical properties of the products were carefully investigated and their catalytic performance was evaluated. The most active sample possesses a bulk Mn/(Mn + Ce) ratio of 74.5 %, which shows a maximum NO conversion of 90.6 % at 270 degrees C (GHSV = 120,000 h(-1)). It is believed that the superior catalytic activity is largely due to the enrichment of Ce element and the high content of Mn4+ species on the surface, while the porous structure is also beneficial.