Chinese Journal of Catalysis

Chinese Journal of Catalysis ›› 2019, Vol. 40 ›› Issue (9): 1395-1404.DOI: 10.1016/S1872-2067(19)63403-0

• Articles • Previous Articles    

Facile immobilization of Ni nanoparticles into mesoporous MCM-41 channels for efficient methane dry reforming

Jingqing Tiana, Haocheng Lia, Xin Zengb, Zichun Wangb,c, Jun Huangb, Chen Zhaoa   

  1. a Shanghai Key Laboratory of Green Chemistry and Chemical Processes, School of Chemistry and Molecular Engineering, East China Normal University, Shanghai 200062, China;
    b Laboratory for Catalysis Engineering, School of Chemical and Biomolecular Engineering, Sydney Nano Institute, The University of Sydney, NSW 2006, Australia;
    c Department of Engineering, Macquarie University, Sydney, New South Wales 2109, AustraliaDepartment of Engineering, Macquarie University, Sydney, New South Wales 2109, Australia
  • Received:2019-02-19 Online:2019-09-18 Published:2019-07-06
  • Contact: S1872-2067(19)63403-0
  • Supported by:
    We appreciate the financial support from the National Key Research and Development Program of China (2016YFB0701100), the Recruitment Program of Global Young Experts in China, and the National Natural Science Foundation of China (21573075). J. H. acknowledges the Australian Research Council Discovery Projects (DP150103842, DP180104010), the SOAR Fellowship, and the Sydney Nano Grand Challenge from the University of Sydney for the support of this project. Z.W. thanks the support by the Australian Research Council Discovery Earlier Career Research Project (DE190101618).

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Abstract: Development of dry reforming of methane and carbon dioxide is an effective route to convert industrial waste gases such as coke-oven gas and coal-to-oil gas into platform syngas. However, this process encounters severe problems of metal particle sintering and coke formation at high temperatures. In this work, we developed a new synthetic method for preparing confined Ni/MCM-41 catalysts, which impede the sintering of metal nanoparticles (NPs) and coke deposition at high temperatures, enabling them to be successfully applied to methane dry reforming. The method results in high activity and stability of the catalyst at 700℃ for 200 h. The Ni precursor is immersed in ethanol and impregnated into MCM-41 by the peculiar capillary action of hexagonal straight mesopores. By this method, 10 wt% Ni NPs (d=2 nm) is equably confined to the mesoporous channels with strong metal-support interactions, as confirmed by HRTEM, TEM mapping, H2-TPR, and XRD measurements. Such a confined structure has a significant effect on the inhibition of metal NP agglomeration and carbon deposition during methane dry reforming, as evidenced by TEM, Raman, TGA, and TPO measurements of used Ni/MCM-41 catalysts. In contrast, unconfined Ni/MCM-41 catalysts, with Ni NPs located on the pore exteriors, are rapidly deactivated after 12 h due to the blocked contact between the active metal centers and the gas feedstock. Additionally, a fast increase in the Ni NP size and the formation of substantial carbon nanotubes on the unconfined catalyst surface are seen. This work offers a facile approach for the synthesis of anti-sintering, carbon-resistant confined Ni catalysts that can operate at high temperatures.

Key words: Dry reforming, Confined structure, Carbon dioxide utilization, Inhibition of carbon deposition, High temperature stable catalyst