NMR study of the chemisorption bond of carbon monoxide on platinum

Abstract

The authors report C13 NMR studies of C13O adsorbed on small Pt particles and show that the data yield quantitative information about the CO-Pt bond. They find that the C13 resonance position is shifted 200 ppm to higher frequency than in CO gas. They prove that the shift arises from polarization of the electron spins in the bond (a Knight shift) by showing that the spin-lattice relaxation obeys the Korringa law. Using ESR results from CO radicals, they deduce the local density of states of the CO 5f orbital on the carbon atom at the Fermi energy. The NMR also reveals diffusion of CO on the Pt surface. © 1985 The American Physical Society.