Departamento de Física de la Materia Condensada, Universidad Autónoma de Madrid, Cantoblanco, 28049 Madrid, Spain.
J Chem Phys. 2012 Aug 21;137(7):074706. doi: 10.1063/1.4746942.
The reactivity of Cu monolayer (ML) and bilayer films grown on Ru(0001) towards O(2) and H(2) has been investigated. O(2) initial sticking coefficients were determined using the King and Wells method in the incident energy range 40-450 meV, and compared to the corresponding values measured on clean Ru(0001) and Cu(111) surfaces. A relative large O(2) sticking coefficient (~0.5-0.8) was measured for 1 ML Cu and even 2 ML Cu/Ru(0001). At low incident energies, this is one order of magnitude larger than the value observed on Cu(111). In contrast, the corresponding reactivity to H(2) was near zero on both Cu monolayer and bilayer films, for incident energies up to 175 meV. Water adsorption on 2 ML Cu/Ru(0001) was found to behave quite differently than on the Ru(0001) and Cu(111) surfaces. Our study shows that Cu/Ru(0001) is a highly selective system, which presents a quite different chemical reactivity towards different species in the same range of collision energies.
我们研究了在 Ru(0001) 上生长的 Cu 单层（ML）和双层膜对 O(2) 和 H(2)的反应性。使用 King 和 Wells 方法在 40-450 meV 的入射能量范围内确定了 O(2) 的初始附着系数，并将其与在清洁 Ru(0001) 和 Cu(111) 表面上测量的相应值进行了比较。对于 1 ML Cu，甚至对于 2 ML Cu/Ru(0001)，测量到相对较大的 O(2)附着系数（~0.5-0.8）。在低入射能量下，这比在 Cu(111)上观察到的值大一个数量级。相比之下，在入射能量高达 175 meV 时，单层和双层 Cu 膜对 H(2)的相应反应性接近零。我们的研究表明，Cu/Ru(0001)是一个高度选择性的体系，在相同的碰撞能量范围内，对不同的物种表现出截然不同的化学反应性。
