Effects of atom-to-defect ratio on the thermostability of dispersed Au atoms on reduced TiO2(1 0 1) surface

Abstract Atomically dispersed metal catalysts (ADCs) with unique electronic structure and unsaturated coordination environments exhibit promising catalytic activity and efficiency. However, the stability of ADCs is a large concern in practical applications because it determines the duration of catalytic performance and the frequency of recycle. In this paper, we provide a lattice-kinetic Monte Carlo method to investigate the stability of dispersed Au atoms on the defective TiO2(1 0 1) surface considering different atom-to-defect ratio. We first show that the Au nanoparticles (NPs) could be dispersed into trapped atoms at the defects through the atomic ripening process, which indicates the possibility of generating ADCs of this system. The Au atoms remained completely dispersed with small ratio of atoms to defects and aggregated to large NPs with large ratio. Interestingly, the Au ADCs remained the dispersed state even if the amount of Au atoms is almost as twice as the number of oxygen vacancies. We thus provide a range of atom-to-defect ratio for the rational design of stable Au ADCs on the reduced TiO2(1 0 1) surface.