TY - GEN
T1 - Self-assembled monolayer of a non-Pt oxygen electroreduction catalyst on metal oxide supports
AU - Gervasio, D. F.
AU - Thomson, Jeffery
PY - 2006
Y1 - 2006
N2 - A self-assembled monolayer (SAM) of metallo porphyrins is intended as a replacement to platinum, in the hope of overcoming the slow oxygen reduction kinetics on Pt that limits fuel-cell efficiency to < 70% [1] and Pt- fouling by impurities. Metallo porphyrins can remedy the problems with Pt in oxygen cathodes [2] but these do not bind on electrode surfaces. A first step to stable catalyst monolayer.is to form a SAM of macrocycle on a current-collecting surface. A cobalt(II) porphyrin, Co1, was formed into a SAM on conductive indium tin oxide (ITO). Co1is attracted to ITO by a covalently attached phosphonate group[3]. Substantial oxygen electro reduction current was found with a SAM of Co1 on ITO compared to bare ITO in 0.01 M aqueous trifluoromethane sulfonic acid (TFMSA) with 1 atm oxygen over solution. The catalytic oxygen reduction current onset at 0.65 V and rose to a limiting current density of about 0.4 milliamp cm-2 at 0.1 V versus RHE. Oxygen reduction on Pt and the Co1 SAM on ITO in aqueous triflic acid in the presence and absence of methanol will be presented to illustrate that the Co1 on ITO is less susceptible to fouling than Pt.
AB - A self-assembled monolayer (SAM) of metallo porphyrins is intended as a replacement to platinum, in the hope of overcoming the slow oxygen reduction kinetics on Pt that limits fuel-cell efficiency to < 70% [1] and Pt- fouling by impurities. Metallo porphyrins can remedy the problems with Pt in oxygen cathodes [2] but these do not bind on electrode surfaces. A first step to stable catalyst monolayer.is to form a SAM of macrocycle on a current-collecting surface. A cobalt(II) porphyrin, Co1, was formed into a SAM on conductive indium tin oxide (ITO). Co1is attracted to ITO by a covalently attached phosphonate group[3]. Substantial oxygen electro reduction current was found with a SAM of Co1 on ITO compared to bare ITO in 0.01 M aqueous trifluoromethane sulfonic acid (TFMSA) with 1 atm oxygen over solution. The catalytic oxygen reduction current onset at 0.65 V and rose to a limiting current density of about 0.4 milliamp cm-2 at 0.1 V versus RHE. Oxygen reduction on Pt and the Co1 SAM on ITO in aqueous triflic acid in the presence and absence of methanol will be presented to illustrate that the Co1 on ITO is less susceptible to fouling than Pt.
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M3 - Conference contribution
AN - SCOPUS:34047248558
SN - 0841274266
SN - 9780841274266
T3 - ACS National Meeting Book of Abstracts
BT - Abstracts of Papers - 232nd American Chemical Society Meeting and Exposition
T2 - 232nd American Chemical Society Meeting and Exposition
Y2 - 10 September 2006 through 14 September 2006
ER -