Adsorption and reaction of CO and O2 on the Ag/Pt(110) surface studied by photoemission electron microscopy

The Ag/Pt(110) model catalyst was prepared by evaporating silver on Pt(110). Adsorption and reaction of CO and O2 on Ag/Pt(110) surface were studied in situ by photoemission electron microscopy (PEEM) during the pressure range of 10 5–10 2 Pa at 480 K. The Ag/Pt(110) surface consisted of Pt(110), AgPt interface and Ag area after annealing at 500 K. The dosing pressure of CO and O2 had a larger influence on their adsorption on the Ag area than on the Pt(110) and AgPt interface. Small Pt clusters formed on the Ag area and AgPt interface, which had a stronger ability to adsorb CO than Pt(110) terrace. The existence of Ag had an obvious influence on the kinetic of CO oxidation on Pt(110). No pattern was observed on the AgPt interface under the same condition when the formation of reaction-diffusion waves occurred on Pt(110).