Key Laboratory for Advanced Materials and Research Institute of Industrial Catalysis, East China University of Science and Technology, 130 Meilong Road, Shanghai, 200237, P.R. China.
Chemical Sciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA.
Angew Chem Int Ed Engl. 2017 Apr 10;56(16):4494-4498. doi: 10.1002/anie.201701191. Epub 2017 Mar 22.
The stabilization of surfactant-assisted synthesized colloidal noble metal nanoparticles (NPs, such as Au NPs) on solids is a promising strategy for preparing supported nanocatalysts for heterogeneous catalysis because of their uniform particle sizes, controllable shapes, and tunable compositions. However, surfactant removal to obtain clean surfaces for catalysis through traditional approaches (such as solvent extraction and thermal decomposition) can easily induce the sintering of NPs, greatly hampering their use in synthesis of novel catalysts. Such unwanted surfactants have now been utilized to stabilize NPs on solids by a simple yet efficient thermal annealing strategy. After being annealed in N flow, the surface-bound surfactants are carbonized in situ as sacrificial architectures that form a conformal coating on NPs and assist in creating an enhanced metal-support interaction between NPs and substrate, thus slowing down the Ostwald ripening process during post-oxidative calcination to remove surface covers.
表面活性剂辅助合成的胶体贵金属纳米粒子（例如 AuNPs）在固体上的稳定化是制备用于多相催化的负载型纳米催化剂的一种很有前途的策略，因为它们具有均匀的粒径、可控的形状和可调的组成。然而，通过传统方法（例如溶剂萃取和热分解）去除表面活性剂以获得用于催化的清洁表面，容易导致纳米粒子的烧结，极大地阻碍了它们在新型催化剂合成中的应用。现在，通过一种简单而有效的热退火策略，已经利用这些不需要的表面活性剂来稳定固体上的纳米粒子。在 N 气流中退火后，表面结合的表面活性剂原位碳化作为牺牲结构，在纳米粒子上形成一个保形涂层，并有助于在纳米粒子和基底之间形成增强的金属-载体相互作用，从而在随后的氧化煅烧过程中减缓奥斯特瓦尔德熟化过程，以去除表面覆盖物。
