“…The detailed information on H 2 -TPR experiments is summarized in Table S5. For Pt/SA sample, the peak I at 128 °C was attributed to the straightforward reduction of surface PtO 2 to metallic platinum . The peak II located at 174 °C was ascribed to the reduction of Pt oxides weakly interacting with alumina surface .…”
Section: Resultsmentioning
confidence: 96%
“…15 Besides, the peak III at 270 °C belonged to the reduction of bulk PtO x such as PtO and PtO 2 species. 7 For Pt/CeSA and Pt/CeO 2 catalysts, the area of all reduction peaks was larger than that of Pt/SA, indicating that not only Pt oxides but also the surface oxygen of ceria were reduced. As is well-known, there is a strong metal− support interaction (SMSI) in noble metal catalysts supported on metal oxides including CeO 2 , TiO 2 , and so on.…”
Section: Industrial and Engineering Chemistry Researchmentioning
confidence: 85%
“…For Pt/SA sample, the peak I at 128 °C was attributed to the straightforward reduction of surface PtO 2 to metallic platinum. 7 The peak II located at 174 °C was ascribed to the reduction of Pt oxides weakly interacting with alumina surface. 15 Besides, the peak III at 270 °C belonged to the reduction of bulk PtO x such as PtO and PtO 2 species.…”
Section: Industrial and Engineering Chemistry Researchmentioning
confidence: 98%
“…The composition of diesel engine exhaust is chemically complex, consisting of CO, NO, unburned hydrocarbons, and particulate matter. − For the increasingly stringent environmental regulations, integrated emission control systems have been widely performed which contain diesel oxidation catalyst (DOC), diesel particulate filters (DPF), and NH 3 selective catalytic reduction (NH 3 -SCR) for lower harmful emissions. , DOC has been primarily utilized to oxidize the harmful emission of hydrocarbons (HC), CO, and NO. Moreover, it is of great importance to increase the amount of NO 2 , which facilitates the low-temperature activity in NH 3 -SCR and promotes soot oxidation in DPF. − …”
Diesel exhaust has recently become a severe problem, and diesel oxidation catalyst (DOC) installed in the diesel exhaust treatment system is used to reduce automobile pollution containing CO, hydrocarbons (HC), and NO. In this work, for the purpose of elucidating the effect of ceria addition on the catalytic performance of Pt-based DOC in CO, HC, and NO oxidation reactions, a range of catalysts were prepared by impregnation method. Among them, the Pt/ 15CeSA catalyst showed excellent catalytic activity, and its NO maximum conversion could reach 62%. The experimental results of X-ray photoelectron spectroscopy (XPS) and highresolution transmission electron microscopy (HRTEM) confirmed that the interface Pt−O−Ce−O−Al existed in the Pt/15CeSA catalyst. Besides, more oxygen vacancies were created at this interface, which were confirmed by oxygen temperature-programmed desorption (O 2 -TPD) and Raman spectroscopic experiments, resulting in an outstanding catalytic performance of Pt/15CeSA. It is expected our research findings will be applied to other oxidation reactions.
“…The detailed information on H 2 -TPR experiments is summarized in Table S5. For Pt/SA sample, the peak I at 128 °C was attributed to the straightforward reduction of surface PtO 2 to metallic platinum . The peak II located at 174 °C was ascribed to the reduction of Pt oxides weakly interacting with alumina surface .…”
Section: Resultsmentioning
confidence: 96%
“…15 Besides, the peak III at 270 °C belonged to the reduction of bulk PtO x such as PtO and PtO 2 species. 7 For Pt/CeSA and Pt/CeO 2 catalysts, the area of all reduction peaks was larger than that of Pt/SA, indicating that not only Pt oxides but also the surface oxygen of ceria were reduced. As is well-known, there is a strong metal− support interaction (SMSI) in noble metal catalysts supported on metal oxides including CeO 2 , TiO 2 , and so on.…”
Section: Industrial and Engineering Chemistry Researchmentioning
confidence: 85%
“…For Pt/SA sample, the peak I at 128 °C was attributed to the straightforward reduction of surface PtO 2 to metallic platinum. 7 The peak II located at 174 °C was ascribed to the reduction of Pt oxides weakly interacting with alumina surface. 15 Besides, the peak III at 270 °C belonged to the reduction of bulk PtO x such as PtO and PtO 2 species.…”
Section: Industrial and Engineering Chemistry Researchmentioning
confidence: 98%
“…The composition of diesel engine exhaust is chemically complex, consisting of CO, NO, unburned hydrocarbons, and particulate matter. − For the increasingly stringent environmental regulations, integrated emission control systems have been widely performed which contain diesel oxidation catalyst (DOC), diesel particulate filters (DPF), and NH 3 selective catalytic reduction (NH 3 -SCR) for lower harmful emissions. , DOC has been primarily utilized to oxidize the harmful emission of hydrocarbons (HC), CO, and NO. Moreover, it is of great importance to increase the amount of NO 2 , which facilitates the low-temperature activity in NH 3 -SCR and promotes soot oxidation in DPF. − …”
Diesel exhaust has recently become a severe problem, and diesel oxidation catalyst (DOC) installed in the diesel exhaust treatment system is used to reduce automobile pollution containing CO, hydrocarbons (HC), and NO. In this work, for the purpose of elucidating the effect of ceria addition on the catalytic performance of Pt-based DOC in CO, HC, and NO oxidation reactions, a range of catalysts were prepared by impregnation method. Among them, the Pt/ 15CeSA catalyst showed excellent catalytic activity, and its NO maximum conversion could reach 62%. The experimental results of X-ray photoelectron spectroscopy (XPS) and highresolution transmission electron microscopy (HRTEM) confirmed that the interface Pt−O−Ce−O−Al existed in the Pt/15CeSA catalyst. Besides, more oxygen vacancies were created at this interface, which were confirmed by oxygen temperature-programmed desorption (O 2 -TPD) and Raman spectroscopic experiments, resulting in an outstanding catalytic performance of Pt/15CeSA. It is expected our research findings will be applied to other oxidation reactions.
“…The increase of the crystallinity indicated that new crystalline phase formed. On the other hand, the growing of the grain of the substrate and the crystalline type tending to be complete after aging may also increase the crystallinity 39 . Figure 3 Crystallinity of the CDPFs before and after aging.…”
Catalyzed diesel particulate filters (CDPFs) have been widespread used as a technically and economically feasible mean for meeting increasingly stringent emissions limits. An important issue affecting the performance of a CDPF is its aging with using time. In this paper, the effects of noble metal loadings, regions and using mileage on the aging performance of a CDPF were investigated by methods of X-ray diffraction (XRD), X-ray photoelectron spectroscopy and catalytic activity evaluation. Results showed that aging of the CDPF shifted the XRD characteristic diffraction peaks towards larger angles and increased the crystallinity, showing a slowing downward trend with the increase of the noble metal loadings. In addition, the increase of the noble metal loading would slow down the decline of Pt and Pt4+ concentration caused by aging. The characteristic temperatures of CO, C3H8 conversion and NO2 production increased after aging, and the more the noble metal loadings, the higher the range of the increase. But noticeably, excessive amounts of noble metals would not present the corresponding anti-aging properties. Specifically, the degree of aging in the inlet region was the deepest, the following is the outlet region, and the middle region was the smallest, which were also reflected in the increase range of crystallinity, characteristic temperatures of CO, C3H8 conversion and NO2 production, as well as the decrease range of Pt and Pt4+ concentrations. The increase of aging mileage reduced the size of the aggregates of the soot and ash in CDPFs, however, improved the degree of tightness between particles. Meanwhile Carbon (C) concentration in the soot and ash increased with the aging mileage.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
