Metallic nature and surface diffusion of CO adsorbed on Ru nanoparticles in aqueous media:: A 13C NMR study

被引：14

作者：

Babu, PK ^{[1
]}

Chung, JH ^{[1
]}

Kuk, ST ^{[1
]}

Kobayashi, T ^{[1
]}

Oldfield, E ^{[1
]}

Wieckowski, A ^{[1
]}

机构：

[1] Univ Illinois, Dept Chem, Urbana, IL 61801 USA

来源：

JOURNAL OF PHYSICAL CHEMISTRY B | 2005年 / 109卷 / 07期

关键词：

D O I：

10.1021/jp040729k

中图分类号：

O64 [物理化学（理论化学）、化学物理学];

学科分类号：

070304 ; 081704 ;

摘要：

We report the first observation of the C-13 nuclear magnetic resonance spectroscopy (NMR) of (CO)-C-13, adsorbed from (CO)-C-13 saturated 0.5 M sulfuric acid solutions, onto the surfaces of commercial Ru-black nanoparticles. The C-13 NMR spectra consist of a symmetrically broadened peak having a large isotropic shift as compared to CO adsorbed onto supported Ru catalysts. The variation of the spin-lattice relaxation rate follows Korringa behavior, indicating the metallic nature of adsorbed CO, in addition to varying across the spectrum in a Korringa-like manner. Motional narrowing of the NMR spectrum at higher temperatures, together with an additional contribution to the spin-lattice relaxation rate, indicate that adsorbed CO undergoes rapid diffusion on the particle surfaces. A two-band model analysis of the NMR results indicates that the CO adsorption bond is weaker on Ru as compared to either Pt or Pd. This is also supported by a reduction in the activation energy for CO diffusion on Ru vs either Pt or Pd nanoparticles.

引用

页码：2474 / 2477

页数：4

共 27 条

[1] Bonding and motional aspects of CO adsorbed on the surface of Pt nanoparticles decorated with Pd [J].