Exchange between sub-surface and surface oxygen vacancies on CeO2(111): a new surface diffusion mechanism

摘要

Using first principles calculations for O vacancy diffusion on CeO2(111), we locate a surface diffusion mechanism, the two-step O vacancy exchange one, which is more favored than the most common hopping mechanism. By analyzing the results, we identify quantitatively the physical origin of why the two-step exchange mechanism is preferred. Surface diffusion, one of the most fundamental processes in physical science, plays key roles in numerous applications.1'2 In particular, comprehension of the diffusion of oxygen