Oxygen and Electron Storage Effects in W‐Modified Ceria Catalysts for Ammonia Conversion

Abstract Tungsten‐modified CeO 2 is an excellent catalyst for the catalytic conversion of ammonia. However, the geometric and electronic properties of this catalyst and the detailed reaction mechanisms are not well understood. In this work, the potential configurations of various monomer tungsten oxides supported on the CeO 2 (111) surface (WO X (x = 0–4)/CeO 2 (111)) are systematically studied and their relative stabilities are evaluated by using on‐site Coulomb interaction corrected density functional theory calculations. Their performances are also investigated in enhancing the catalytic efficiency of NH 3 adsorption and activation. It is found that the WO x clusters can always form tetrahedron‐like structures on the CeO 2 (111) surface, and the CeO 2 (111) can exhibit both oxygen‐ and electron‐storage roles to help the WO X maintain such tetrahedron‐like WO 4 structures and keep the W species at the highest 6+ state. Moreover, the flexibility of the tetrahedral WO 4 structure leads to the preferential heterolytic NH 3 dissociation at the WO sites, forming stable WNH 2 and OH species. This study deepens the understanding of the unique oxygen‐ and electron‐storage effects of the CeO 2 support, it also provides valuable insights into the extraordinary catalytic properties of the W‐modified CeO 2 in NH 3 conversion, paving the way for the rational design of more efficient CeO 2 ‐based NH 3 treatment catalysts.