Electronic state of silver in Ag/SiO 2 and Ag/ZnO catalysts and its effect on diesel particulate matter oxidation: An XPS study

Corro, Grisel; Vidal, Esmeralda; Cebada, Surinam; Pal, U.; Bañuelos, Fortino; Vargas, Diana Gabriela; Guilleminot, Emmanuel

doi:10.1016/j.apcatb.2017.05.059

Cited by 107 publications

(45 citation statements)

References 49 publications

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“…3(b) shows the Ag 3d 5/ 2 and Ag 3d 3/2 peaks at 368.1 eV and 374.1 eV, respectively, which are consistent with silver atoms in the zerovalent state (Ag 3d 5/2 ¼ $368.0 eV). 50,51 Deconvolution of the high resolution spectrum of S 2p spectrum, shown in Fig. 3(c), shows two peaks with spin-orbit splitting of $1.2 eV indicating the presence of Ag-thiolate species (162.2 eV for S 2p 3/2 and 163.5 eV for S 2p 1/ 2 ).…”

Section: Resultsmentioning

confidence: 98%

Activation of atomically precise silver clusters on carbon supports for styrene oxidation reactions

2019

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Section: Resultsmentioning

confidence: 98%

Activation of atomically precise silver clusters on carbon supports for styrene oxidation reactions

2019

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“…The XRD is a research method to obtain the information of material composition, internal atomic or molecular structure or morphology through the analysis of X-ray diffraction and diffraction patterns, which can accurately measure the crystal structure and crystal size 32 . The XPS is an effective method to measure the composition and chemical state of surface elements of the materials by quantitatively evaluating the binding energy peak intensity and peak displacement of different atoms or molecule 33 . The catalytic activity evaluation based on temperature-programmed reduction (TPR) system is an effective method to quantitatively analyze the catalytic activity of the catalyst 34 .…”

Section: Experimental Methodsmentioning

confidence: 99%

Study of spatial and temporal aging characteristic of catalyzed diesel particulate filter catalytic performance used for diesel vehicle

Zhang

Lou

Tan

et al. 2020

Sci Rep

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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.

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“…These species could have been formed during the calcination process, probably due to the reducing environment of the zirconia hydrogel-containing surface OH groups, and the low stability of the Ag oxides at high temperature. Corro et al propose that the Ag 0 formation is associated with the low enthalpy of formation of Ag2O at high temperature [71]. In previous studies, it has been reported that the reducibility of transition metal species increases on ZrO2 [26,72].…”

Section: Ag O + H ( ) ↔ H O ( ) + 2agmentioning

confidence: 99%

Zirconia-Supported Silver Nanoparticles for the Catalytic Combustion of Pollutants Originating from Mobile Sources

et al. 2019

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This work presents the physicochemical characterization and activity of zirconia-supported silver catalysts for the oxidation of pollutants present in diesel engine exhaust (propane, propene, naphthalene and soot). A series of silver-supported catalysts AgxZ (x = 1, 5 and 10 wt.%, Z = zirconia) were prepared, which were studied by various characterization techniques. The results show that silver is mainly found under the form of small metal nanoparticles (<10 nm) dispersed over the support. The metallic phase coexists with the AgOx oxidic phases. Silver is introduced onto the zirconia, generating Ag–ZrO2 catalysts with high activity for the oxidation of propene and naphthalene. These catalysts also show some activity for soot combustion. Silver species can contribute with zirconia in the catalytic redox cycle, through a synergistic effect, providing sites that facilitate the migration and availability of oxygen, which is favored by the presence of structural defects. This is a novel application of the AgOx–Ag/ZrO2 system in the combustion reaction of propene and naphthalene. The results are highly promising, given that the T50 values found for both model molecules are quite low.

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Electronic state of silver in Ag/SiO 2 and Ag/ZnO catalysts and its effect on diesel particulate matter oxidation: An XPS study

Cited by 107 publications

References 49 publications

Activation of atomically precise silver clusters on carbon supports for styrene oxidation reactions

Activation of atomically precise silver clusters on carbon supports for styrene oxidation reactions

Study of spatial and temporal aging characteristic of catalyzed diesel particulate filter catalytic performance used for diesel vehicle

Zirconia-Supported Silver Nanoparticles for the Catalytic Combustion of Pollutants Originating from Mobile Sources

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