NO electronic desorption processes from step sites on Pt(112): A comparison between photo‐ and electron‐stimulated desorption
NO electronic desorption processes from step sites on Pt(112): A comparison between photo‐ and electron‐stimulated desorption
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Pt(112) 上台阶位点的 NO 电子解吸过程：光刺激解吸与电子刺激解吸之间的比较
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发表时间：
1994
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影响因子：
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通讯作者：
J. Yates
中科院分区：
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作者：
U. Heiz;Jiazhan Xu;J. W. Gadzuk;J. Yates
用傅里叶变换红外反射吸收光谱作为表面分析方法，测量了在铂(112)台阶上吸附NO的特定化学吸附物种的光致和电子激发脱附总截面。对这些光解吸和电子激发脱附的物种截面进行了比较。对于光刺激解吸，获得了意想不到的结果，使用3.5eV的光子；桥接-无解吸体的横截面(1.1x10−22cm2)高于末端-NO(6.1x10−23cm2)。对于电子激发脱附，使用能量为275 eV的电子，则观察到相反的情况。末端无解吸体，横截面积(2.3×10−18cm2)大于桥接无解吸体，横截面积为8.7x10−19cm2。在‘’热电子‘’模型下讨论了光激发过程，并假定较强结合的桥联-NO产生的较高的−(A)物种的预期猝灭速率超过了预期猝灭速率。
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...