Chinese Journal of Catalysis

Chinese Journal of Catalysis ›› 2016, Vol. 37 ›› Issue (5): 743-749.DOI: 10.1016/S1872-2067(15)61071-3

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Synthesis of Ni-CeO2 catalyst for the partial oxidation of methane using RF thermal plasma

M. Y. Leea, J. S. Namb, J. H. Seoa,b   

  1. a Department of Applied Plasma Engineering, Chonbuk National University, Jeonbuk 54896, Korea;
    b Department of Quantum System Engineering, Chonbuk National University, Jeonbuk 54896, Korea
  • Received:2016-01-04 Revised:2016-02-23 Online:2016-04-26 Published:2016-04-26
  • Contact: J. H. Seo

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Abstract:

Ni-CeO2 catalysts with a nickel content of 50 mol% were prepared using RF thermal plasma, and their catalytic activities for methane partial oxidation were characterized. For the synthesis of Ni-CeO2 catalysts, a precursor containing Ni (~5-μm diameter) and CeO2 (~200-nm diameter) powders were heated simultaneously using an RF plasma at a power level of ~52 kVA and a powder feeding rate of ~120 g/h. From the X-ray diffraction data and transmission electron microscopy images, the precursor formed into high crystalline CeO2 supports with nanosized Ni particles (< 50-nm diameter) on their surfaces. The catalytic performance was evaluated under atmospheric pressure at > 500 ℃ and a CH4:O2 molar ratio of 2:1 with Ar diluent. Although the Ni content was high (~50 mol%), the experimental results reveal a methane conversion rate of > 70%, selectivities of CO and H2 greater than 90% and slight carbon coking during an on-stream test at 550 ℃ for 24 h. However, at 750 ℃, the on-stream test revealed the formation of filament-like carbons with an increased methane conversion rate over 90%.

Key words: RF thermal plasma, Methane, Partial oxidation, Nickel catalyst, Ceria, Carbon deposition