(197aj) Exploring the Factors behind Adsorbate-Adsorbate Interactions

In heterogeneous catalysis, adsorbate-adsorbate interaction can greatly affect reaction rates. Understanding such interactions are crucial for determining intrinsic kinetics and catalytic activity. Herein, we present a model for the interaction among small adsorbates such as C, H, and O on the Pt(111) surface. This model considers the modification of the metal surface and the adsorption strength resulting from other adsorbates in the vicinity of the adsorption site. For the same adsorbates, the binding energy of the metal atoms of the active site decreases as the number of C, H, or O adsorbates in their surroundings on the Pt(111) surface increases. Specifically, the binding energy decreases from -6.4371 to -5.4003 eV for C, from -6.4371 to -6.3351 eV for H, and from -6.4371 to -5.2154 eV for O. It is noteworthy that the presence of other adsorbates can significantly affect the behavior of a specific adsorbate, these effects cannot be explained solely by the electronic structure. The electrostatic interactions among various adsorbates also play a crucial role. Remarkably, the changes in the predicted and calculated C, H, and O adsorption energy on the Pt(111) surface in the presence of other adsorbates exhibit a linear scaling behavior with the number of adsorbates in the surroundings, indicating that the electrostatic interactions among various adsorbates depend on the type and number of interacting adsorbates. When the same type of adsorbates are present, such as C-C, O-O, and H-H, the repulsive nature between them is greater than that between different types of adsorbates, such as C-O, C-H, and O-H. The influence of the electronic and electrostatic components on the adsorbate-adsorbate interaction is more pronounced for C and O, while it is less significant for H. The electronic and electrostatic effects can be determined by simple scaling with number of adsorbates, and the metal binding energies can be utilized to predict the adsorbate binding energies (Figure 1). By considering the electronic and electrostatic components and the presence of different types of adsorbates, the model offers a significant advantage of predicting the adsorbate-adsorbate interaction. Ultimately, this can be achieved without the need for extensive computational calculations, making it a valuable tool for both theoreticians and experimentalists in the field of heterogeneous catalysis.