The Thermal gravimetric analysis (TGA) with In-situ Fourier transform infrared Spectrometer (In-FTIR) of fresh/hydrothermal aging Ce-based catalysts was carried out for the soot oxidation at different transi-tion metal Mn, alkali metals K, precious metals Ag and rare earth metal Zr doping which used to extend the hydrothermal aging resistance of CeO2 catalysts. The comprehensive combustion index S , combustion stability index Rw and peak temperature Tp from TG-DTG curves were extracted to evaluate the soot cat-alytic combustion performance, and the NO2/NO ratio during the combustion process was also measured to analyze the NOx synergistic oxidation performance. The effect of metal oxide doping type, doping ratio and hydrothermal aging time on S, R-w, T-p and NO2/NO ratio was evaluated to reveal the change in soot catalytic combustion performance. The result shows that, compared with PU, the NOx synergistic oxida-tion performance of various metal oxides modified Ce-based catalysts ranked as K > Ag > Mn > Zr. With the metal oxide doping ratio increased, the soot catalytic combustion performance of K and Zr metal ox-ides modified Ce-based catalysts decreased, Mn and Ag metal oxides modified catalyst increased. After hydrothermal aging treatment, the NOx synergistic oxidation performance of various metal oxides modi-fied Ce-based catalysts ranked as K > Ag > Mn > Zr. This work is helpful to reveal the basic mechanism of hydrothermal aging metal oxide modified Ce-based catalyst and NOx during soot catalytic combustion process. (C) 2022 The Combustion Institute. Published by Elsevier Inc. All rights reserved.
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