In this paper, we use Fourier transform infrared (FTIR) spectroscopy and stripping voltammetry at saturation
and submonolayer CO coverages to shed light on the influence of size on the CO adsorption and electro-oxidation on Pt nanoparticles. Pt nanoparticles supported on low surface area (∼1 m2 g-1) carbon (Sibunit)
are used throughout the study. The vibrational spectra of adsorbed CO are dominated by interparticle
heterogeneity (contribution of particles of different size in the range from 0.5 to 5 nm) rather than intraparticle
heterogeneity (contribution of different adsorption sites). CO stripping voltammetry exhibits two peaks separated
by approximately 0.25 V (at 0.02 V s-1), which are attributed to the CO oxidation from “large” (∼3.6 nm)
and “small” (∼1.7 nm) Pt nanoparticles. Using stepwise oxidation, we were able to separate the contributions
of “large” and “small” nanoparticles and obtain their infrared and voltammetric “fingerprints”. Considerable
differences are observed between “large” and “small” nanoparticles in terms of (i) the vibrational frequencies
of adsorbed CO molecules (ii) their vibrational coupling, and (iii) CO oxidation overpotential.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.