College of Chemistry and Life Sciences, Zhejiang Normal University, Key Lab of Advanced Catalytic Materials of Ministry of Education, Jinhua 321004, China.
College of Chemistry and Life Sciences, Zhejiang Normal University, Key Lab of Advanced Catalytic Materials of Ministry of Education, Jinhua 321004, China.
J Colloid Interface Sci. 2018 Feb 15;512:775-783. doi: 10.1016/j.jcis.2017.09.098. Epub 2017 Sep 28.
How to design and develop ceria supported metal nanoparticles (M/CeO) 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/CeO catalysts. One is to introduce Ti atom on CeO (1 1 1) to form monatomically dispersed Ti, TiO or TiO-like species on ceria. Density functional theory calculations show that the much stronger interactions between Au and Ti modified CeO (1 1 1) occur compared with that on CeO (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 CeO (1 1 1) to form TiCeO. This also leads to the interaction enhancement between Au and TiCeO (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/CeO catalysts with high dispersity and stability, and sheds light into the theoretical design of catalysts.
如何设计和开发具有高性能和抗烧结性的氧化铈负载金属纳米粒子（M/CeO）催化剂是多相催化和表面科学领域的一大挑战。在本工作中，我们提出了两种提高 M/CeO 催化剂抗烧结能力的方法。一种是在 CeO（111）上引入 Ti 原子，在 CeO 上形成单分散的 Ti、TiO 或 TiO 类似物种。密度泛函理论计算表明，与 CeO（111）相比，Au 与 Ti 修饰的 CeO（111）之间的相互作用要强得多。根据电子分析，这种强相互作用归因于 Ti 修饰的 CeO 基质向 Au 的电子转移。另一种是将 Ti 掺杂到 CeO（111）中形成 TiCeO。这也导致了 Au 和 TiCeO（111）之间相互作用的增强。电子分析表明，Ti 原子附近表面 O 原子的电荷突出导致了金属和 CeO 之间的强相互作用。这项工作为制备高分散度和稳定性的 M/CeO 催化剂提供了新的思路，并为催化剂的理论设计提供了启示。
