The methanation reaction is widely recognized as having significant implications for carbon dioxide capture. In this context, the development of affordable and efficient catalysts is highly desirable. Furthermore, understanding the surface behavior of catalysts and the influence of specific modifications on their reactivity is of great interest. Thus, this study focuses on investigating the effect of the Ni/CeO2 mesoporous structure on the redox properties of Ni0 and Ni2+-CeO2 interfacial sites. This is because they are responsible for the presence of reducible species and surface oxygen vacancies, respectively, both of which are required for CO2 methanation. Our results highlight the critical role of mesopores in determining the proper balance of these active species on the catalyst surface, leading to enhanced reactivity under an appropriate temperature range. To substantiate our observations, in-situ NAP-XPS experiments were performed to study in detail the surface changes of the active species as a function of both chemical environment and temperature. Therefore, it was demonstrated that this spectroscopic technique provides valuable insights into the concave surface behavior for monitoring reactivity on mesoporous catalysts, allowing us to contribute to the advancement of methanation reaction technology using CO2.