Synergistic Effects of Multicomponents Produce Outstanding Soot Oxidation Activity in a Cs/Co/MnOx Catalyst.

Abstract

The control of soot emission from diesel vehicles is of extraordinary importance to the environment, and catalytic removal of soot is a highly effective and clean method. Here, we report a novel, non-noble metal catalyst for application in the catalytic combustion of soot with superb activity and resistance to H2O and SO2. MnOx oxide was prepared via a hydrothermal method, and then, Cs and Co were loaded on MnOx by impregnation. The 5%Cs/1%Co/MnOx catalyst displayed excellent catalytic activity with values of T10 (332 °C), T50 (371 °C), and T90 (415 °C) under loose contact. The as-prepared catalysts were investigated by X-ray powder diffraction (XRD), transmission electron microscopy (TEM), H2 temperature-programmed reduction (TPR), O2 temperature-programmed desorption (TPD), X-ray photoelectron spectroscopy (XPS), and X-ray absorption fine structure (XAFS). The results suggest that, after the introduction of Cs and Co into the MnOx oxide, more NO2 molecules take part in soot oxidation, exhibiting higher NO2 utilization efficiency; this is due to the synergistic effects of multiple components (Cs, Co, and Mn) promoting the generation of more surface-active oxygen and then accelerating the reaction between NO2 and soot. This study provides significant insights into the development of high-efficiency catalysts for soot oxidation, and the developed 5%Cs/1%Co/MnOx catalyst is a promising candidate for application in diesel particulate filters.