THE STABILIZATION OF FORMATE ON PT(111) BY COADSORBED ATOMIC OXYGEN

We have studied the stabilization of adsorbed formate in the presence of coadsorbed atomic oxygen on Pt(111) using the techniques of thermal desorption spectroscopy and high-resolution electron energy loss spec troscopy. The increased stability manifests itself in two primary ways : the temperatures at which formic acid converts to formate, and forma te converts to gaseous CO2, are lower and higher, respectively, than i n the absence of oxygen; and the saturation yields of dehydrogenation products are approximately five times greater than those produced on t he clean surface. The latter effect is coupled to an apparent increase in the sticking coefficient of the molecular acid.