Chinese Journal of Catalysis

Chinese Journal of Catalysis ›› 2017, Vol. 38 ›› Issue (3): 545-553.DOI: 10.1016/S1872-2067(17)62762-1

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Gold nanoparticle stabilization within tailored cubic mesoporous silica: Optimizing alcohol oxidation activity

Wei Honga, Xiaoqing Yanb, Renhong Lia,b, Jie Fana   

  1. a Key Laboratory of Applied Chemistry of Zhejiang Province, Department of Chemistry, Zhejiang University, Hangzhou 310027, Zhejiang, China;
    b Key Laboratory of Advanced Textile Materials and Manufacturing Technology, Ministry of Education of China, Zhejiang Sci-Tech University, Hangzhou 310018, Zhejiang, China
  • Received:2016-10-20 Revised:2016-12-06 Online:2017-03-18 Published:2017-03-22
  • Supported by:

    This work was supported by the National Natural Science Foundation of China (21222307, 21373181, 21403197, 91545113, 21503189), the Fundamental Research Funds for the Central Universities (2014XZZX003-02), Zhejiang Provincial Natural Science Foundation (LY15B030009), and China Postdoctoral Science Foundation (2014M550333, 2015T80636).

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Abstract:

Stabilizing gold nanoparticles (AuNPs) within a desired size range is critical to realize their promising catalytic performance in many important reactions. Herein, we investigate the anti-sintering properties of cubic mesoporous silica (FDU-12) as a function of pore entrance size. Simple adjustments to the type of organic template and reaction temperature enable the successful synthesis of FDU-12 with controllable entrance sizes (< 3, 3-5 and 7 nm). Excellent anti-sintering properties are observed for FDU-12 with a sub-5-nm entrance size (3-5 nm) over a wide loading concentration (1.0-8.3 wt%) and the AuNPs can be stabilized within a 4.5-5.0-nm range after calcination at 550℃ in air for 5 h. Smaller entrance size (< 3 nm) prevents ingress of 3-nm AuNPs to the mesopores and results in low loading capacity and sintering. Conversely, FDU-12 possessing a larger entrance size (7 nm) shows promising anti-sintering properties at high loading concentrations, although catalytic performance is significantly lost at lower concentrations (e.g. 2.1 wt%, 14.2 ± 5.5 nm). Different anti-sintering mechanisms are proposed for each of the different FDU-12 entrance sizes. Additionally, catalytic data indicates that the obtained 4.5-nm AuNPs supported on FDU-12 with a sub-5-nm entrance size exhibit excellent mass-specific activity (1544 mmol gAu-1 h-1) and selectivity (> 99%) at 230℃ for the gas-phase selective oxidation of cyclohexanol.

Key words: Gold nanoparticle, Cubic mesoporous silica, Entrance size, Anti-sintering property, Alcohol oxidation