Carbon-supported Pt-Sn electrocatalysts for the anodic oxidation of H2, CO, and H2/CO mixtures

The catalytic activity of 3 different C-supported Pt-Sn catalysts for the anodic oxidn. of hydrogen, CO, and H2/CO mixts. is correlated with the bimetallic microstructure established in Part I [V. Radmilovic, T. J. Richardson, S. J. Chen, P. N. Ross, Jr. (2005)] of this study. These catalysts differ primarily by having differing amts. of Pt, Pt3Sn, PtSn, and SnO2 phase nanoparticles distributed on the C support. Further surface chem. characterization of the Pt3Sn nanoparticles is provided by comparison of in situ vibrational spectra of CO adsorbed on the nanoparticles with CO adsorbed on Pt3Sn(hkl) surfaces [V. Stamenkovic, et al. (2005 and 2003)]. Qual. measures of CO oxidn. activity were also obtained from the FTIR spectra for the electrode potential at which CO2 is 1st detected (appearance potential). Quant. kinetic measurements using the C-supported catalysts were obtained with the thin-film rotating disk electrode (TF-RDE) method. The COad stripping voltammetry clearly indicated that the 500N sample exhibits the lowest degree of alloying, showing a superposition of Pt3Sn and Pt features, whereas the catalyst consisting entirely of stoichiometric Pt3Sn cubic phase (E270 sample) exhibits no features characteristic of pure Pt. None of the 3 C-supported Pt-Sn catalysts had the splitting of the C=O stretching band of characteristic of COad on Pt3Sn(111), the surface with the highest specific activity (turnover no.) for CO and H2/CO oxidn. All 3 catalysts had very high levels of activity for H2 oxidn. The mass activity for CO and H2/CO oxidn. was proportional to the amt. of Pt3Sn phase in the catalyst. There is no clear evidence that either the PtSn phase or Pt/SnO2 clusters contribute any significant activity for H2/CO or CO oxidn. in these catalysts. [on SciFinder(R)]     «

The catalytic activity of 3 different C-supported Pt-Sn catalysts for the anodic oxidn. of hydrogen, CO, and H2/CO mixts. is correlated with the bimetallic microstructure established in Part I [V. Radmilovic, T. J. Richardson, S. J. Chen, P. N. Ross, Jr. (2005)] of this study. These catalysts differ primarily by having differing amts. of Pt, Pt3Sn, PtSn, and SnO2 phase nanoparticles distributed on the C support. Further surface chem. characterization of the Pt3Sn nanoparticles is provided by com...     »

Adsorbed substances (IR spectra of adsorbed CO on Pt-Sn electrocatalysts) Carbon black Role: CAT (Catalyst use), USES (Uses) (carbon-supported Pt-Sn electrocatalysts for anodic oxidn. of H2, CO, and H2/CO mixts.) Oxidation catalysts (electrochem. Pt-Sn alloys for H2, CO, and H2/CO mixts.) Oxidation (of H2, CO, and H2/CO mixts. on heat-treated Pt-Sn alloys) Particle size distribution (of Pt-Sn alloy electrocatalysts supported on carbon) Heat treatment (of Pt-Sn alloys for electrocatalytic oxidn. of H2, CO, and H2/CO mixts.) IR spectra (of adsorbed CO on Pt-Sn electrocatalysts) carbon supported platinum tin electrocatalyst electrooxidn hydrogen carbon monoxide     «

Adsorbed substances (IR spectra of adsorbed CO on Pt-Sn electrocatalysts) Carbon black Role: CAT (Catalyst use), USES (Uses) (carbon-supported Pt-Sn electrocatalysts for anodic oxidn. of H2, CO, and H2/CO mixts.) Oxidation catalysts (electrochem. Pt-Sn alloys for H2, CO, and H2/CO mixts.) Oxidation (of H2, CO, and H2/CO mixts. on heat-treated Pt-Sn alloys) Particle size distribution (of Pt-Sn alloy electrocatalysts supported on carbon) Heat treatment (of Pt-Sn alloys for electrocatalytic oxidn....     »

CAN 143:141350 72-2 Electrochemistry Materials Science Division, Lawrence Berkeley National Laboratory, University of California, Berkeley, CA, USA. Journal 0021-9517 37365-43-8 (Platinum 50, tin 50 (atomic)); 37365-44-9 (Platinum 75, tin 25 (atomic)) Role: DEV (Device component use), USES (Uses) (carbon-supported Pt-Sn electrocatalysts for anodic oxidn. of H2, CO, and H2/CO mixts.); 630-08-0 (Carbon monoxide); 1333-74-0 (Hydrogen) Role: RCT (Reactant), RACT (Reactant or reagent) (carbon-supported heat-treated Pt-Sn electrocatalysts for anodic oxidn. of H2, CO, and H2/CO mixts.); 12038-27-6 (Ptsn); 12210-67-2; 18282-10-5 (Tin dioxide) Role: FMU (Formation, unclassified), PRP (Properties), FORM (Formation, nonpreparative) (phase in heat-treated Pt-Sn and electrocatalysts for anodic oxidn. of H2, CO and H2/CO mixts.); 124-38-9P (Carbon dioxide) Role: PNU (Preparation, unclassified), PREP (Preparation) (prepn. in anodic oxidn. of CO and H2/CO mixts.)     «

CAN 143:141350 72-2 Electrochemistry Materials Science Division, Lawrence Berkeley National Laboratory, University of California, Berkeley, CA, USA. Journal 0021-9517 37365-43-8 (Platinum 50, tin 50 (atomic)); 37365-44-9 (Platinum 75, tin 25 (atomic)) Role: DEV (Device component use), USES (Uses) (carbon-supported Pt-Sn electrocatalysts for anodic oxidn. of H2, CO, and H2/CO mixts.); 630-08-0 (Carbon monoxide); 1333-74-0 (Hydrogen) Role: RCT (Reactant), RACT (Reactant or reagent) (carbon-supp...     »