A SENSITIVE METHOD FOR MEASURING ADSORBED CARBON ON PALLADIUM SURFACES - TITRATION BY NO

Small quantities of adsorbed C have been deposited on Pd(112) by the dissociative adsorption of C2H4. It is demonstrated that although Auger electron spectroscopy is insensitive to the presence of this C(ads), temperature programmed desorption (TPD) can be used to determine the cleanliness of the surface. TPD spectra following the 300 K adsorption of NO on C-covered Pd(112) indicate that reactive chemistry occurs during heating, as evidenced by the production of high temperature N2(≈590 K) and CO (≈520 K) thermal desorption features. The results of this study are used to formulate an improved method for the removal of C from Pd surfaces in ultrahigh vacuum. © 1995, American Vacuum Society. All rights reserved.