Interaction of Water with Ceria Thin Film

Abstract Water interaction with ceria is a fundamental process underpinning catalytic reactions such as water‐gas‐shift and water electrolysis. This review summarizes the investigations of water interactions with the ceria low‐index surfaces [(111), (100), and (110)]. The first part introduces: (a) The atomic structures of the stoichiometric CeO 2 and reduced CeO x (x=1.5∼2) thin films, including the characteristics of oxygen vacancies; (b) The anisotropic migration mechanisms of oxygen vacancies and the locations of the entangled polarons in the reduced ceria. The second part reviews water‘s adsorption, desorption, dissociation, and redox properties on the ceria low‐index surfaces studied by DFT, TPD, XPS, RPES, TEM, and SPM methods. The impacts of water coverage, ceria film thickness, strain effect, dopant effect, face stability, and solid‐liquid interface on the interaction between water and ceria are also discussed. At last, this review sheds some light on the future directions and challenges in this topic.