Interfacing Surface Electrochemistry with Solid-State NMR. Characterization of Surface CO on Polycrystalline Platinum

✍ Scribed by P.J. Slezak; A. Wieckowski

• Publisher: Elsevier Science
• Year: 1993
• Tongue: English
• Weight: 799 KB
• Volume: 102
• Category: Article
• ISSN: 1064-1858
• DOI: 10.1006/jmra.1993.1086

✦ Synopsis

A single-channel NMR probe and an electrochemical cell were built to interface surface electrochemistry to NMR. Using a 300 MHz solid-state NMR instrument with a spin-echo pulse sequence and an electrochemical cell configuration, ({ }^{13} \mathrm{C})-enriched carbon monoxide adsorbates as a function of the electrode potential were monitored. The adsorbates were obtained via catalytic decomposition of ({ }^{13} \mathrm{C})-enriched methanol on a high-surfacearea electrode made of powdered platinum. Narrowing of the solid-like NMR peak of the surface (\mathrm{CO}) at more positive potentials was observed. This has been interpreted to result from a transformation of a mixed, predominantly bridge- and linearbonded (\mathrm{CO}) population to essentially a linear-bonded (\mathrm{CO}). It has been shown that the ({ }^{13} \mathrm{CO}) adsorbate is stable in a natural (\left({ }^{12} \mathrm{C}\right)) methanol environment even at relatively high electrode potentials, which demonstrates that an exchange of surface (\mathrm{CO}) with solution methanol is practically absent. C 1993 Academic Press. Inc.