Collision‐induced desorption of ammonia chemisorbed on Pt{111}: From direct measurement of the threshold energy to determination of the surface–adsorbate bond strength
Collision‐induced desorption of ammonia chemisorbed on Pt{111}: From direct measurement of the threshold energy to determination of the surface–adsorbate bond strength
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Pt{111} 上化学吸附的氨的碰撞诱导解吸：从阈值能量的直接测量到表面吸附物键强度的测定
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发表时间：
1995
期刊：
影响因子：
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通讯作者：
R. Levis
中科院分区：
文献类型：
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作者：
G. Szulczewski;R. Levis
我们报告的解吸化学吸附的多原子吸附物从过渡金属表面的中性，高能Ar原子束。通过直接测量碰撞诱导脱附的阈值能量，我们计算了表面吸附物的键能。在0°、30°、45°和60°的入射角下，测量了Ar束能量高达103 eV时，在单层覆盖率的四分之一处NH3解吸的绝对截面。对于NH_3/Pt{111}吸附物-表面系统，阈值脱附能为1.95± 0.17eV。使用经典的能量转移机制，该阈值能量对应于使用1个Pt原子的有效质量的1.1±0.1 eV的键能。阈值脱附能量与每个入射角的惰性气体原子的总能量成比例。这一结果与NH3/Pt{111}势能面中的强横向散射和每个角度处的类似喷射机制是一致的。
We report the desorption of a chemisorbed polyatomic adsorbate from a transition metal surface by a beam of neutral, energetic Ar atoms. From direct measurement of the threshold energy for collision‐induced desorption we calculate the surface–adsorbate bond energy. The absolute cross sections for NH3 desorption at one‐quarter of a monolayer coverage were measured for Ar beam energies up to ∼3 eV at incident angles of 0°, 30°, 45°, and 60°. For the NH3/Pt{111} adsorbate–surface system, the threshold desorption energy is found to be 1.95±0.17 eV. Using a classical energy transfer mechanism this threshold energy corresponds to a bond energy of 1.1±0.1 eV using an effective mass of 1 Pt atom. The threshold desorption energy scales with the total energy of the noble gas atoms for each angle of incidence. This result is consistent with a strong lateral corrugation in the NH3/Pt{111} potential energy surface and a similar ejection mechanism at each angle.