Sibunit Family

doo2 from 0.348 to 0.352 nm, and /002/210 from 5.0 to 7.5. At the same time, they may have high surface areas (up to 500 m /g) and pore volume (up to 1.0 cm /g). Notably, micropore volume in Sibunit carbons does not exceed 

1 cm /g. The technology of Sibunit production allows one to vary textural characteristics, adsorption properties, and mechanical stiffness widely by varying the type of template, the degree of solidification, and the degree of activation. 

CARBON MATERIALS AS SUPPORTS FOR FUEL CELL ELECTROCATALYSTS 

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Figure 15.1 High resolution transmission electron microscopy images (HR-TEM) of 5 wt% Pd (a) and 50 wt% Pt-Ru (b) particles supported on carbon supports of the Sibunit family with surface areas of about 6m g (a) and 72m g (b). (c) Fourier-transformed image of (b). ((a) Reprinted from Pronkin et al. [2007], Copyright 2007, with permission from Elsevier, (b) and (c) reprinted from Gavrilov et al. [2007]—Reproduced by permission of the PCCP Owner Societies.)...

Another reason, which affects the utilization factor, is the structure of the carbon particles themselves. Rao et al. [17] have demonstrated that the catalyst utilization factor may vary significantly depending on the porosity of carbon materials. They have prepared a series of Pt-Ru (1 1) catalysts supported on carbon materials from the Sibunit family with grossly different BET surface areas, ranging from 20 to 400 m /g, which were utilized as the anode catalysts in liquid-fed DMFC. To be able to distinguish between the influence on cell performance of the metal dispersion and the carbon support porosity, the metal dispersion was kept constant and close to 0.3. It was demonstrated that the catalyst utiUzation factor reached 100% for low-surface-area supports but dropped down to 10% for the high-surface-area Sibunit carbon. As a result, in methanol electrooxidation, both the mass activity (Ag Ru) and specific activity increased with a... 

Finally, we addressed the complex problem of carbon corrosion, which is particularly relevant for PEMFC durability and thus commercialization of PEMFC technology. Carbon supports with an ordered crystalline structure, such as graphi-tized carbons, CNTs, and CNFs, as well as pyrolytic carbons of the Sibunit family hold out hope for the development of CLs with higher durability. More systematic studies are required to unveil the complex influence of the structure and morphology of carbon supports on the performance of the CLs and eventually, to develop a new generation of structurally ordered tailored materials for PEMFC applications with enhanced catalytic activities, low noble metal contents, and high dmabilities. 

Anodic Reactions in Electrocatalysis -Oxidation of Carbon Monoxide, Fig. 1 Plot of a-top C-O band wavenumber versus the CO fractional surface coverage for (a) nanometer-sized Pt particles supported on pyrolytic carbon of Sibunit family and (b) Pt(557) = Pt [6(lll)x(100)] single crystal (Reproduced from Refs. [4, 17] with permission of the American Chemical Society)... 

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