A new insight into the theoretical design of highly dispersed and stable ceria supported metal nanoparticles

How to design and develop ceria supported metal nanoparticles (M/CeO₂) catalysts with high performance and sintering resistance is a great challenge in heterogeneous catalysis and surface science. In the present work, we propose two ways to improve the anti-sintering capability of M/CeO₂ catalysts. One is to introduce Ti atom on CeO₂ (1 1 1) to form monatomically dispersed Ti, TiO_x or TiO₂-like species on ceria. Density functional theory calculations show that the much stronger interactions between Au and Ti modified CeO₂ (1 1 1) occur compared with that on CeO₂ (1 1 1). According to the electronic analysis, the strong interactions are attributed to the electron transfer from the Ti modified ceria substrate to Au. The other is to dope Ti into CeO₂ (1 1 1) to form Ti_xCe_1-xO₂. This also leads to the interaction enhancement between Au and Ti_xCe_1-xO₂ (1 1 1). Electronic analysis indicates that the charge protuberance of surface O atoms near Ti atom results in the strong interactions between metal and ceria. This work provides new ideas for preparing M/CeO₂ catalysts with high dispersity and stability, and sheds light into the theoretical design of catalysts.