Enhanced reactivity of adsorbed oxygen on Pd(111) induced by compression of the oxygen layer
نویسندگان
چکیده
The reaction between O atoms and CO molecules on Pd 111 was investigated by scanning tunneling microscopy STM . CO was dosed on the 2 2 O-covered surface at temperatures between 100 and 190 K, and the structure changes were monitored by STM. CO adsorption causes compression of the 2 2 O overlayer into islands of the 2 1 O structure, followed by reaction of the O atoms to give CO2. The 2 2 O overlayer does not react with CO at temperatures up to 180 K, whereas the 2 1 O phase reacts at temperatures as low as 136 K. The analysis of the reaction kinetics reveals an activation energy for the O+CO reaction of 0.4 eV and a reaction order of 1 with respect to the O coverage.
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