Soot surface area evolution during air oxidation as evaluated by small angle X-ray scattering and CO2 adsorption

Kandas, Angelo W.; Şenel, İsmet; Levendis, Yiannis A.; Sarofim, Adel F.

doi:10.1016/j.carbon.2004.08.028

Cited by 51 publications

(33 citation statements)

References 29 publications

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“…Accordingly, it is presumed that the crystallite ordering process progressed up to a certain degree of oxidation and the carbon crystallites were stabilized despite continued oxidation. The stabilized structures at the late oxidation stage may indicate that physical properties such as density and surface area remained invariant with further oxidation, as Kandas et al [5] and Strzelec et al [6] observed. It is interesting to note that the Raman spectra of the 90%-oxidized sample with 2500 ppm NO 2 is quite comparable to those of the 33%-oxidized samples with O 2 only/1000 ppm NO 2 addition.…”

Section: Raman Analysis Of Partially Oxidized Sootmentioning

confidence: 81%

“…Correspondingly, Hurt et al described that oxidation reaction, processed by breaking bonds and removing carbon atoms as well as cross links, promotes graphitization through atomic rearrangement [3]. As a result, there observed a significant increase in surface area up to a certain degree of oxidation [4][5][6], because volatilization of adsorbed compounds allows the access of oxidizers into internal pores, facilitating opening of closed pores with preferential oxidation of less-ordered parts [5,7]. Indeed, soot maturity during oxidation was evident by many studies using Raman spectroscopy [8][9][10], X-ray diffraction (XRD) [11,12] and transmission electron microscopy (TEM) [2,8,11,12].…”

Section: Introductionmentioning

confidence: 95%

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Oxidation-derived maturing process of soot, dependent on O2–NO2 mixtures and temperatures

Seong

Choi

2015

Carbon

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a b s t r a c tOxidizer-and temperature-dependent soot properties were investigated to better understand soot oxidation process. For this work, partially oxidized Printex-U samples as surrogate soot, under three different O 2 -NO 2 mixtures, were analyzed by using the high resolution-transmission electron microscope, Raman microscope and Fourier transform infrared spectroscopy-attenuated total reflectance. The results show that the maturing process was much dependent on NO 2 content in the O 2 -NO 2 mixture: with no NO 2 added, soot oxidized through the internal-burning out process, whereas with increased NO 2 in the mixture, soot tended to oxidize through the external burning process. As the NO 2 content increased, the preferential oxidation of less-ordered carbon crystallites decreased and as a result the maturing process was delayed. Internal burning-out process by O 2 only was also verified at various temperatures and with actual engine soot such as diesel soot and gasoline direct-injection (GDI) soot by TEM observations. Despite similar internal burning-out process, however, it was shown that oxidation at increased temperature resulted in relatively less-ordered soot, implying that soot maturing process was delayed with temperature. Since soot oxidation rate increased with temperature, the increase in oxidation temperature seems to diminish preference on short-ranged crystallites like more efficient O 2 -NO 2 cases.

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Section: Raman Analysis Of Partially Oxidized Sootmentioning

confidence: 81%

Section: Introductionmentioning

confidence: 95%

Oxidation-derived maturing process of soot, dependent on O2–NO2 mixtures and temperatures

Seong

Choi

2015

Carbon

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“…Soot carbon particles are formed from agglomerates of spherules composed of graphite-like microcrystallites. They consist almost exclusively of carbon, with minor amounts of hydrogen and oxygen (Ogren and Charlson, 1983;Andreae and Gelencsér, 2006) and are characterized by a surface area well above 10 m 2 g −1 with maximum values ≥ 100 m 2 g −1 , depending on the combustion source (e.g., Gilot et al, 1993;Popovitcheva et al, 2000;Kandas et al, 2005). Note that this definition excludes any organic species that might be present as a coating on the spherules.…”

Section: Current Terminologymentioning

confidence: 99%

Recommendations for reporting "black carbon" measurements

Petzold¹,

et al. 2013

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Abstract. Although black carbon (BC) is one of the key atmospheric particulate components driving climate change and air quality, there is no agreement on the terminology that considers all aspects of specific properties, definitions, measurement methods, and related uncertainties. As a result, there is much ambiguity in the scientific literature of measurements and numerical models that refer to BC with different names and based on different properties of the particles, with no clear definition of the terms. The authors present here a recommended terminology to clarify the terms used for BC in atmospheric research, with the goal of establishing unambiguous links between terms, targeted material properties and associated measurement techniques.

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“…Particulate composition is another important factor affecting the particle oxidative reactivity. Volatile matter such as hydrocarbons that filled the micropores on the particulate is a source of further micropore development and hence creating a variation in particle reactivity (Stanmore et al 2001;Kandas et al 2005).…”

Section: Introductionmentioning

confidence: 99%

Investigation on Particulate Oxidation from a DI Diesel Engine Fueled with Three Fuels

Tian

Cheung

Huang

2012

Aerosol Science and Technology

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In this study, particles generated from a direct-injection (DI) diesel engine fueled with biodiesel, ultra-low-sulfur diesel (ULSD, <10 ppm-wt), and low-sulfur diesel (LSD, <500 ppm-wt) were investigated experimentally for their oxidation properties, using the thermogravimetric analysis (TGA), at five engine loads. Kinetic analysis of particulate oxidation was conducted based on the mass loss curves obtained from the TGA. The activation energy was found to be in the range of 142-175, 76-127, and 133-162 kJ/mol for the particulate samples for ULSD, biodiesel, and LSD, respectively. The particulate oxidation rate decreases with the increase of engine load for each fuel, and at each engine load, the oxidation rate decreases in the order of biodiesel, LSD, and ULSD. The primary particle size, nanostructure, and volatile fraction were also investigated for different particulate samples. The results indicate that the higher oxidation rate of biodiesel particles could be related to the smaller primary particle size, the more disordered nanostructure, and the larger volatile fraction, compared with the ULSD and LSD particles. The increase of sulfur content in a diesel fuel has a limited influence on primary particle size and nanostructure, while inducing a larger volatile fraction, which might be one of the reasons for the stronger oxidative reactivity of the LSD particles, compared with the ULSD particles.

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Soot surface area evolution during air oxidation as evaluated by small angle X-ray scattering and CO2 adsorption

Cited by 51 publications

References 29 publications

Oxidation-derived maturing process of soot, dependent on O2–NO2 mixtures and temperatures

Oxidation-derived maturing process of soot, dependent on O2–NO2 mixtures and temperatures

Recommendations for reporting "black carbon" measurements

Investigation on Particulate Oxidation from a DI Diesel Engine Fueled with Three Fuels

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Soot surface area evolution during air oxidation as evaluated by small angle X-ray scattering and CO2 adsorption

Cited by 51 publications

References 29 publications

Oxidation-derived maturing process of soot, dependent on O2–NO2 mixtures and temperatures

Oxidation-derived maturing process of soot, dependent on O2–NO2 mixtures and temperatures

Recommendations for reporting &quot;black carbon&quot; measurements

Investigation on Particulate Oxidation from a DI Diesel Engine Fueled with Three Fuels

Contact Info

Product

Resources

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Recommendations for reporting "black carbon" measurements