Curulla Ferré Daniel, van Bavel Alexandre P, Niemantsverdriet J W
Schuit Institute of Catalysis, Technische Universiteit Eindhoven, P.O. Box 513, 5600 MB Eindhoven, The Netherlands
Chemphyschem. 2005 Mar;6(3):473-80. doi: 10.1002/cphc.200400399.
The interaction between adsorbates is a key issue in surface science, because these interactions can influence strongly the properties of chemisorbed species with consequences for the thermodynamics and kinetics of surface processes. The simplest representation of adsorbate-adsorbate interactions is based on the assumption that all interactions are pairwise additive. This approach has been satisfactorily used in the modeling of temperature-programmed desorption (TPD) spectra using both continuum and Monte Carlo methods. However, the energies estimated within the pairwise approximation have never been compared to the energies calculated using density functional theory (DFT) methods. We demonstrate that the pairwise additive potential approximation is indeed a good representation of the adsorbate-adsorbate interactions, and that we do not need to include three-body interactions or higher-order terms to estimate the perturbation of the adsorption energy of an adsorbate by the presence of other coadsorbates. Moreover, we show for the first time how DFT can be used to explain the desorption features that one finds in TPD experiments, thus linking the TPD desorption features with actual microscopic configurations.
吸附质之间的相互作用是表面科学中的一个关键问题，因为这些相互作用会强烈影响化学吸附物种的性质，进而影响表面过程的热力学和动力学。吸附质 - 吸附质相互作用的最简单表示基于所有相互作用都是成对加和的假设。这种方法已在使用连续介质和蒙特卡罗方法对程序升温脱附（TPD）光谱进行建模时得到了令人满意的应用。然而，在成对近似内估计的能量从未与使用密度泛函理论（DFT）方法计算的能量进行过比较。我们证明，成对加和势近似确实很好地表示了吸附质 - 吸附质相互作用，并且我们无需包含三体相互作用或高阶项来估计其他共吸附质的存在对吸附质吸附能量的扰动。此外，我们首次展示了如何使用DFT来解释在TPD实验中发现的脱附特征，从而将TPD脱附特征与实际微观构型联系起来。
