Formation and Behavior of Carbonates on Ag(110) in the Presence of Ethylene and Oxygen

Intermediate species formed on Ag(110) surfaces under the presence of ethylene and oxygen in the sub-Torr pressure range were studied by near-ambient-pressure X-ray photoelectron spectroscopy (XPS) and near-edge X-ray absorption fine structure (NEXAFS) measurements. Carbonates are clearly observed exclusively under an ethylene-rich condition (0.2 Torr ethylene and 0.04 Torr oxygen; ethylene/oxygen = 5) at a high temperature of 500 K or relatively low-temperature conditions (<= 470 K) at an oxygen-rich gas ratio (ethylene/oxygen = 1/5). NEXAFS results support the formation of carbonates and indicate that the carbonates are adsorbed almost parallel to the Ag(110) surface. The carbonates coexist with surface oxides with different composition ratios depending on the ethylene/ oxygen pressure ratio and surface temperature. From these results we propose that the carbonates are formed by reaction(s) between ethylene and oxygen on the Ag(110) surface.

Automated summary

The formation of intermediate species on Ag(110) surfaces under the presence of ethylene and oxygen in the sub-Torr pressure range was studied using near-ambient-pressure XPS and NEXAFS measurements. Carbonates were observed mainly under ethylene-rich conditions, adsorbed almost parallel to the Ag(110) surface. These carbonates coexist with surface oxides, with different composition ratios depending on the ethylene/oxygen pressure ratio and surface temperature.