Journal of Hydrogen and New Energy (한국수소및신에너지학회논문집)

The Korean Hydrogen and New Energy Society (한국수소및신에너지학회)
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Hydrogen Production from Ammonia Decomposition over Transition Metal Carbides

전이금속 카바이드를 이용한 암모니아 분해 반응으로부터 수소생산

  • CHOI, EUI-JI (Department of Chemical Engineering, Hannam University) ;
  • CHOI, JEONG-GIL (Department of Chemical Engineering, Hannam University)
  • 최의지 (한남대학교 화학공학과) ;
  • 최정길 (한남대학교 화학공학과)
  • Received : 2018.12.08
  • Accepted : 2019.02.28
  • Published : 2019.02.28
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Abstract

The preparation and catalytic activities of various transition metal carbide crystallites (VC, MoC, WC) were examined in this study. In particular, the effect of different kinds of transition metal crystallites were scrutinized on the ammonia decomposition reaction. The experimental results showed that BET surface areas ranged from $8.3m^2/g$ to $36.3m^2/g$ and oxygen uptake values varied from $9.1{\mu}mol/g$ to $25.4{\mu}mol/g$. Amongst prepared transition metal carbide crystallites, tungsten compounds (WC) were observed to be most active for ammonia decomposition reaction. The main reason for these results were considered to be related to the extent of electronegativity between these materials. Most of transition metal carbide crystallites were exceeded by Pt/C crystallite. However, the steady state reactivities for some of transition metal carbide crystallites (WC) were comparable to or even higher than that determined for the Pt/C crystallite.

Keywords

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Fig. 1. Surface area and oxygen uptake for tungsten carbides

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Fig. 3. Surface area and oxygen uptake for tungsten carbides

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Fig. 2. Ammonia decomposition conversion as a function of surface area

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Fig. 4. SEM results for (a) fresh WC (×5,000) and (b) aged WC (×5,000)

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Fig. 5. XRD results for W oxides (a, b) and for W carbides (c, d)

Table 1. Synthesis conditions of catalysts

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Table 2. Surface properties of catalysts

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Table 3. NH3 decomposition conversion for various catalysts

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References

  1. N. I. I1'chenko, "Oxidative Catalysis on Transition-Metal Carbides", Kinetics and Catalysis, Vol. 18, No. 1, 1977, pp. 153-163.
  2. L. leclercq, K. Imura, S. Yoshida, T. Barbee, and M. Boudart, "Preparation of Catalysts II", Elsevier, USA, 1978, p. 627.
  3. D. J. Sajkowski and S. T. Oyama, "Symposium on the Chemistry of W/Mo Catalysis", Prep. Petrol. Chem. Div., 199th ACS Nat. Meeting, Vol. 35, No. 2, 1990, p. 233.
  4. J. G. Choi, "The Influences of Surface Composition on HDN Activities of Molybdenum Nitrides", Journal of Industrial and Engineering Chemistry, Vol. 8, No. 1, 2002, pp. 1-11. Retrieved from https://www.cheric.org/research/tech/periodicals/view.php?seq=362649.
  5. L. Volpe and M. Boudart, "Ammonia Synthesis on Molybdenum Nitrides", J. Phys. Chem., Vol. 90, No. 20, 2015, pp. 4874-4877, doi: http://dx.doi.org/10.1021/j100411a031.
  6. R. B. Levy and M. Boudart, "Platinum-Like Behavior of t ungsten Carbide in Surface Catalysis", Science, Vol. 181, No. 4099, 1973, pp. 547-549, doi: http://dx.doi.org/10.1126/science.181.4099.547.
  7. J. H. Singelt and D. J. C. Yates, "Effect of Carbiding on the Hydrogenolysis Activity of Molybdenum", Nature Phys. Sci., Vol. 229, 1971, pp. 27-28, doi: https://doi.org/10.1038/physci229027b0.
  8. L. E. Toth, "Transition Metal Carbides and Nitrides", Academic Press, USA, 1971, p. 234.
  9. P. A. Armstrong, A. T. Bell, and J. A. Reimer, "Comparison of the dynamics and orientation of chemisorbed benzene and pyridine on molybdenum nitride (.gamma.-Mo2N)", J. Phys. Chem., Vol. 97, No. 9, 1993, pp. 1952-1960, doi: http://dx.doi.org/10.1021/j100111a037.
  10. J. G. Choi, J. Ha, and J. W. Hong, "Synthesis and catalytic properties of vanadium interstitial compounds", Applied Catalysis A: General, Vol. 168, No. 1, 1998, pp. 47-56, doi: https://doi.org/10.1016/S0926-860X(97)00332-3.
  11. L. H. Bennett, J. R. Cuthill, A. J. McAlister, N. E. Erickson, and R. E. Watson, "Electronic structure and catalytic behavior of tungsten carbide", Science, Vol. 184, No. 4136, 1974, pp. 563-565, doi: http://dx.doi.org/10.1126/science.184.4136.563.
  12. J. B. Claridge, A. P. E. York, A. J. Brungs, and M. L. H. Green, "Study of the Temperature-Programmed Reaction Synthesis of Early Transition Metal carbide and Nitride Catalyst Materials from Oxide Precursors", Chem. Mater., Vol. 12, No. 1, 2000, pp. 132-142, doi: http://dx.doi.org/10.1021/cm9911060.