Login
- Title:
The Effect of the Particle Size on the Kinetics of CO Electrooxidation on High Surface Area Pt Catalysts
- Document type:
- Zeitschriftenaufsatz
- Author(s):
- Arenz, Matthias; Mayrhofer, Karl J. J.; Stamenkovic, Vojislav; Blizanac, Berislav B.; Tomoyuki, Tada; Ross, Phil N.; Markovic, Nenad M.
- Abstract:
- Using high-resoln. TEM, IR reflection-absorption spectroscopy (IRAS), and electrochem. (EC) measurements, Pt nanoparticles ranging in size from 1 to 30 nm are characterized and their catalytic activity for CO electrooxidn. is evaluated. TEM anal. reveals that Pt crystallites are not perfect cubooctahedrons, and that large particles have rougher surfaces than small particles, which have some fairly smooth (111) facets. The importance of defect sites for the catalytic properties of nanoparticles is probed in IRAS expts. by monitoring how the vibrational frequencies of atop CO (vCO) as well as the concomitant development of dissolved CO2 are affected by the no. of defects on the Pt nanoparticles. Defects play a significant role in CO clustering on nanoparticles, causing CO to decrease/increase in local coverage, which yields to anomalous red shift/blueshift vCO frequency deviations from the normal Stark-tuning behavior. The obsd. deviations are accompanied by CO2 prodn., which increases by increasing the no. of defects on the nanoparticles, i.e., 1 ≤ 2 < 5 .mchlt. 30 nm. Probably the catalytic activity for CO adlayer oxidn. is predominantly influenced by the ability of the surface to dissoc. H2O and to form OHad on defect sites rather than by CO energetics. These results are complemented by chronoamperometric and rotating disk electrode (RDE) data. In contrast to CO stripping expts., in the backsweep of CO bulk oxidn., the activity increases with decreasing particle size, i.e., with increasing oxophilicity of the particles. [on SciFinder(R)]
- Keywords:
- Annealing (Pt nanoparticle pretreated by CO annealing and effect of nanoparticle size on kinetics of CO electrooxidn. on high surface area Pt catalysts) Adsorbed substances (chronoamperometry in CO adlayer electrochem. oxidn. on platinum nanoparticles in HClO4 soln.) Oxidation (effect of nanoparticle size on CO electrooxidn. on high surface area Pt catalysts studied by high-resoln. transmission electron microscopy, IR reflection-absorption spectroscopy, and electrochem. measurements) IR spectra... »
- Congress title:
- CAN 143:34053 72-2 Electrochemistry Materials Science Division, Lawrence Berkeley National Laboratory, University of California, Berkeley, CA, USA. Journal 0002-7863 3352-57-6 (Hydroxyl) Role: CPS (Chemical process), PEP (Physical, engineering or chemical process), PROC (Process) (adsorbed hydroxyl in adsorbed CO electrochem. oxidn. and effect of nanoparticle size on kinetics of CO electrooxidn. on high surface area Pt catalysts); 7601-90-3 (Perchloric acid) Role: NUU (Other use, unclassified),... »
- Journal title:
- J. Am. Chem. Soc.
- Year:
- 2005
- Journal volume:
- 127
- Journal issue:
- 18
- Pages contribution:
- 6819-6829
- Fulltext / DOI:
- doi:10.1021/ja043602h
BibTeX