Kaust Catalysis Center (KCC), Physical Science and Engineering Division (PSE), King Abdullah University of Science and Technology (KAUST), Thuwal 23955-6900, Saudi Arabia.
Phys Chem Chem Phys. 2019 Nov 28;21(44):24429-24440. doi: 10.1039/c9cp04470a. Epub 2019 Nov 1.
A platinum complex, (CH)Pt(COD), is grafted via surface organometallic chemistry (SOMC) on morphology-controlled anatase TiO to generate single, isolated Pt atoms on TiO nano-platelets. The resulting material is characterized by FT-IR, high resolution scanning transmission electron microscopy (HRSTEM), NMR, and XAS, and then used to perform photocatalytic water splitting. The photocatalyst with SOMC-grafted Pt shows superior performance in photocatalytic hydrogen evolution and strongly suppresses the backwards reaction of H and O forming HO under dark conditions, compared to the photocatalyst prepared by impregnation at the same Pt loading. However, single Pt atoms on this surface also rapidly coalesce into nanoparticles under photocatalytic conditions. It is also found that adsorption of CO gas at room temperature also triggers the aggregation of Pt single atoms into nanoparticles. A detailed mechanism is investigated for the mobility of Pt in the formation of its carbonyls using density functional theory (DFT) calculations.
通过表面有机金属化学（SOMC），将（CH）Pt（COD）铂配合物接枝到形态控制的锐钛矿 TiO 上，在 TiO 纳米板上生成单分散的孤立 Pt 原子。通过傅里叶变换红外光谱（FT-IR）、高分辨率扫描透射电子显微镜（HRSTEM）、NMR 和 XAS 对所得材料进行了表征，然后将其用于光催化水分解。与在相同 Pt 负载下通过浸渍法制备的光催化剂相比，具有 SOMC 接枝 Pt 的光催化剂在光催化析氢反应中表现出优异的性能，并强烈抑制了 H 和 O 在黑暗条件下形成 HO 的反向反应。然而，在光催化条件下，该表面上的单个 Pt 原子也迅速聚集成纳米颗粒。还发现，室温下 CO 气体的吸附也会引发 Pt 单原子聚集成纳米颗粒。使用密度泛函理论（DFT）计算研究了在形成其羰基化合物过程中 Pt 的迁移性的详细机理。
