Researchers Discover Size-dependent Strong Metal-support Interaction
Strong metal-support interaction (SMSI) is an important concept in heterogeneous catalysis, which is not only decisive in stabilizing active metals on supports, but also important in tuning catalytic performance and studying reaction mechanisms.
Au had been regarded as an inert metal for SMSI in the past few decades due to its relatively lower work function and surface energy. As a dynamic process taking place at the interface between Au nanoparticles(NPs) and the support, SMSI is closely related to the surface properties of Au NP, which is profoundly influenced by the Au NP size. Therefore, it was proposed that the occurrence of SMSI would follow a size effect.
Recently, a group led by Prof. QIAO Botao cooperated with a group led by Prof. LI Gao from the Dalian Institute of Chemical Physics (DICP) of the Chinese Academy of Sciences (CAS) discovered a size effect on classical SMSI in Au/TiO2 catalysts, which provides a new approach to refine catalyst performance.
The results were published in Nature Communications on Nov. 16.
The researchers controllably synthesized Au/TiO2 catalysts with different size distribution and investigated their SMSI performance.
It was found that SMSI was more prone to occur on large Au NPs (~9 and ~13 nm) than on small ones (~3 and ~7 nm). A surface tension dependent thermodynamic equilibrium model was established to explain this size effect.
Furthermore, the hydrogenation reaction selectivity of Au/TiO2 catalyst with an uneven particle size distribution was effectively improved by selectively encapsulating the large Au NPs as well as tuning the electronic property of the small ones.
This work may bring an in-depth understanding of SMSI mechanism, and provide an alternative approach to refine catalytic performance by tuning the SMSI state.
This study was supported by National Key Projects for Fundamental Research and Development of China, Strategic Priority Research Program of the Chinese Academy of Sciences, National Natural Science Foundation of China, DNL Cooperation Fund, LiaoNing Revitalization Talents Program, Innovation Fund of DICP, and Natural Science Foundation of China, China Postdoctoral Science Foundation.
Dalian Institute of Chemical Physics, Chinese Academy of Sciences
457 Zhongshan Road, Dalian, 116023, China
Tel: 86-411-84374221
E-mail: wangyj@dicp.ac.cn
