Adsorption and reaction of CO and O-2 on the Ag/Pt(110) surface studied byphotoemission electron microscopy

The Ag/Pt(110) model catalyst was prepared by evaporating silver on Pt(110) . Adsorption and reaction of CO and O-2 on Ag/Pt(110) surface were studied in situ by photoemission electron microscopy (PEEM) during the pressure ran ge 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 O-2 had a larger influence on their adsorption on the Ag area th an on the Pt(110) and AgPt Interface. Small Pt clusters formed on the Ag ar ea and AgPt interface, which had a stronger ability to adsorb CO than Pt(11 0) 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 unde r the same condition when the formation of reaction-diffusion waves occurre d on Pt(110).