NO electronic desorption processes from step sites on Pt(112): A comparison between photo‐ and electron‐stimulated desorption
| Autor: | J. W. Gadzuk, J. Xu, J. T. Yates, U. Heiz |
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| Rok vydání: | 1994 |
| Předmět: | |
| Zdroj: | The Journal of Chemical Physics. 101:4373-4378 |
| ISSN: | 1089-7690 0021-9606 |
| DOI: | 10.1063/1.467488 |
| Popis: | Using Fourier‐transform infrared reflectance absorption spectroscopy as a surface analytical method, the total photo‐ and electron‐stimulated desorption cross sections for specific chemisorbed NO species on the steps of Pt(112) have been measured. These species‐specific cross sections for photo‐ and electron stimulated desorption are compared with each other. An unexpected result was obtained for photo‐stimulated desorption, using photons with an energy of 3.5 eV; bridged‐NO desorbs with a higher cross section (1.1×10−22 cm2) than terminal‐NO (6.1×10−23 cm2). For electron stimulated desorption, using electrons of an energy of 275 eV, the opposite is observed. Terminal‐NO desorbs with a higher cross section (2.3×10−18 cm2) than bridged‐NO, with a cross section of 8.7×10−19 cm2. The photo‐stimulated process is discussed within the ‘‘hot electron’’ model, and it is postulated that the higher expected quenching rate of the NO−(a) species produced from the more strongly‐bound bridged‐NO is more than compensate... |
| Databáze: | OpenAIRE |
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