Degreening Effect During NO Oxidation over Pt/Al2O3 Catalyst

作者：Jia Liwei^*; Wan Taoming; Wang Jun; Shen Meiqing; Wang Jianqiang; Wang Jiaming

来源：Rare Metal Materials and Engineering, 2018, 47(5): 1562-1566.

• diesel oxidation catalysts
• degreening effect
• Pt/Al2O3 catalysts
• NO oxidation

Part of NO is oxidized to NO2 when the emission gas goes through diesel oxidation catalysts (DOC). Proper NO2/NOx concentration increases the low-temperature soot oxidation rate of diesel particulate filter (DPF) and the NOx conversion efficiency of selective catalytic reduction catalyst (SCR). In order to study the degreening effect of DOC, in-situ diffuse reflectance infrared Fourier transform spectroscopy (In-situ DRFTS), H-2 temperature-programmed reduction (H-2-TPR), X-ray photoelectron spectroscopy (XPS) and High-revolution transmission electron microscope (HR-TEM) were used to characterize the Pt/Al2O3 catalyst. Results show that a large amount of nitrate and nitrite species are accumulated in the fresh Pt/Al2O3 catalysts below 300 degrees C, which causes the low activity of fresh catalysts. The decomposition of PtOx species that interacts strongly with the substrate is the main cause of degreening effect after one temperature-programmed reaction. The particle size of Pt has no significant change after 3-cycle temperature-programmed reaction.

• 出版日期2018-5
• 单位天津大学