Stages in the Modification of a Silver Surface for Catalysis of the Partial Oxidation of Ethylene: II. Action of the Reaction Medium

摘要: The modification of clean silver foil by C2H4 + O2 and CO reaction mixtures has been studied XPS, TPD, TPR. It shown that treatment activates the surface for ethylene oxide formation. This is accompanied formation a number species (carbonates, elementary carbon adsorbed oxygen), as well dissolution oxygen atoms in bulk. Displacement mixture comparison composition after action both indicates active centre contains two states with different ionicity AgO bond. "Ionic" [Eb(O 1s) = 528.4 eV] produces Ag+ ions sites adsorption, while "covalent" 530.5 seems to react form oxide. A possible mechanism influence factors (surface composition, morphology, etc.) on this process are discussed.