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Bao X von Deak D Biddinger EJ Ozkan US Hadad CM 《Chemical communications (Cambridge, England)》2010,46(45):8621-8623
Oxygen reduction reaction (ORR) over a carbonaceous catalyst (1) with a phosphinate (>P(=O)OH) moiety was explored computationally. Under the acidic environment of a fuel cell, 1 could be active for ORR and be converted to 2 with a >P(OH)(2) moiety. An edge phosphinate could be active for both 2- and 4-electron ORR. 相似文献
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BłAŻEJ JAN WRÓBEL 《Proceedings Mathematical Sciences》2011,121(1):45-75
We examine weighted L
p
boundedness of g-functions based on semigroups related to multi-dimensional Laguerre function expansions of Hermite type. A technique of vector-valued
Calderón–Zygmund operators is used. 相似文献
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Matter PH Wang E Arias M Biddinger EJ Ozkan US 《The journal of physical chemistry. B》2006,110(37):18374-18384
Noble-metal-free active catalysts for the oxygen reduction reaction (ORR) in an acidic environment were prepared from the pyrolysis of acetonitrile at 900 degrees C over alumina and metal-doped alumina. This work includes analyses of the nitrogen-doped carbon preparation process, characterization of the carbon materials formed, and activity testing for the ORR. The nitrogen-containing carbon nanostructures that formed during the pyrolysis of acetonitrile could be purified by washing the product with hydrofluoric acid. A wide range of techniques were used to characterize the solid carbon products of the acetonitrile decomposition. While the samples have many similar physical properties, X-ray photoelectron spectroscopy and transmission electron microscopy showed evidence that differences in the nanostructure and surface functional groups of the samples are likely to account for observed differences in oxygen reduction activity. The most active catalysts were prepared over alumina impregnated with up to 2 wt % Fe, although the catalysts that were prepared by acetonitrile pyrolysis over alumina with no metal doping still had significant activity. In comparison to a 20 wt % platinum on Vulcan carbon catalyst, the most active samples only have an additional 100 mV overpotential. The selectivity of the catalysts for complete oxygen reduction to water followed a trend similar to activity. The best selectivity to water versus peroxide obtained was 99%, or equivalently, an n of 3.98 (i.e., 3.98 electrons transferred out of a maximum of 4 electrons per mole of oxygen that is reduced), as determined by rotating ring-disk electrode testing. 相似文献
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