Journal of Physical Chemistry, Vol.98, No.43, 11011-11014, 1994
Hydrogen Adsorption on Platinum Particles Studied by Pt-195 NMR
A 4.4 wt % platinum on anatase catalyst with average particle size 1.7 nm is studied by Pt-195 NMR after increasing dosing with hydrogen (H/surface Pt ratios of 0.1, 0.5, and 1). Both spectral changes and variations of T-1 at the maximum of the spectrum are observed. The relaxation curves are not single exponential but show Korringa-type time/temperature scaling, indicating that all platinum atoms are in a metallic environment. It is concluded that there is a very large distribution of local densities of state at the Fermi energy on different surface atoms and that the values are still lower than found previously.