Vincent Jonathan K, Olsen Roar A, Kroes Geert-Jan, Luppi Marcello, Baerends Evert-Jan
Leiden Institute of Chemistry, Gorlaeus Laboratories, Leiden University, P.O. Box 9502, 2300 RA Leiden, The Netherlands.
J Chem Phys. 2005 Jan 22;122(4):44701. doi: 10.1063/1.1834914.
Six-dimensional quantum dynamics calculations on dissociative chemisorption of H(2) on Ru(0001) are performed. The six-dimensional potential energy surface is generated using density functional theory. Two different generalized gradient approximations are used, i.e., RPBE and PW91, to allow the results to be compared. The dissociation probability for normally incident H(2) on a clean Ru(0001) surface is calculated. Large differences between the reaction probabilities calculated using the RPBE and PW91 are seen, with the PW91 results showing a much narrower reaction probability curve and a much higher reactivity. Using the reaction probabilities and assuming normal energy scaling reaction rates are generated for temperatures between 300 and 800 K. The rate generated using the PW91 results is higher by about a factor 5 than the rate based on the RPBE results in the range of temperatures relevant to ammonia production.
对H₂在Ru(0001)上的解离化学吸附进行了六维量子动力学计算。使用密度泛函理论生成了六维势能面。采用了两种不同的广义梯度近似，即RPBE和PW91，以便对结果进行比较。计算了正常入射的H₂在清洁Ru(0001)表面上的解离概率。可以看到，使用RPBE和PW91计算得到的反应概率存在很大差异，PW91的结果显示反应概率曲线更窄，反应活性更高。利用反应概率并假设正常能量标度，生成了300至800 K温度范围内的反应速率。在与氨生产相关的温度范围内，使用PW91结果生成的速率比基于RPBE结果的速率高约5倍。
