Microkinetic modelling plays the key role to bridge first principles calculations at the atomic level to experimental data at macroscopic scales. Currently, some significant differences between the microkinetic modelling results and experimental ones still exist. In this work, CO oxidation on Rh(111) is selected as a model system for its simplicity as well as its importance, and an in-depth study of microkinetic modelling on the reaction is performed. A self-consistent microkinetic modelling iterating with respect to coverages is developed. It is found that a good accuracy of the microkinetic modelling using density functional theory energies can be obtained if adsorbate-adsorbate interactions including the coverage effect on the transition states are rigorously calculated. The calculated kinetic results including the turnover frequency (TOF), which are very close to experimental ones, can be achieved if corrections of the over-estimation of chemisorption energies of density functional theory and van der Waals forces are also included.

No abstract

No abstract

Main observation and conclusion As a common electrocatalytic system, Au‐Pt alloy particles are often prepared as Au‐core‐Pt‐shell (Au@Pt) to make full use of platinum. However, Au has a strong tendency to segregate to the outer surface, leading to the redistribution of the active sites. Unfortunately, the mechanism of such reconstruction and its effect on the electrocatalytic activity have not been thoroughly discussed, largely owing to the complexity of in‐situ characterization and computational modeling. Herein, by taking the 55‐atom Au13Pt42 core‐shell nanocluster as an example, we utilized the neural network potential at density functional theory (DFT) level and the genetic algorithm to search the complex global configurational space. It turns out that it is thermodynamically favorable when all gold atoms are segregated to the surface and the shape of the cluster tends to change from icosahedron to a distorted amorphous structure (at a reduced core, DRC) with a unique gold distribution. Towards understanding the dynamic activity variation of oxygen reduction reaction (ORR) on this bimetallic Au@Pt system, oxygen adsorption energy calculations show that this reconstruction could not only increase the number of adsorption sites but also dramatically improve the ORR catalytic activity of each site, thus enhance the overall ORR reactivity.

No abstract