DOI QR코드

DOI QR Code

전이금속 카바이드를 이용한 암모니아 분해 반응으로부터 수소생산

Hydrogen Production from Ammonia Decomposition over Transition Metal Carbides

  • 최의지 (한남대학교 화학공학과) ;
  • 최정길 (한남대학교 화학공학과)
  • CHOI, EUI-JI (Department of Chemical Engineering, Hannam University) ;
  • CHOI, JEONG-GIL (Department of Chemical Engineering, Hannam University)
  • 투고 : 2018.12.08
  • 심사 : 2019.02.28
  • 발행 : 2019.02.28

초록

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.

키워드

SSONB2_2019_v30n1_1_f0001.png 이미지

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

SSONB2_2019_v30n1_1_f0002.png 이미지

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

SSONB2_2019_v30n1_1_f0003.png 이미지

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

SSONB2_2019_v30n1_1_f0004.png 이미지

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

SSONB2_2019_v30n1_1_f0005.png 이미지

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

Table 1. Synthesis conditions of catalysts

SSONB2_2019_v30n1_1_t0001.png 이미지

Table 2. Surface properties of catalysts

SSONB2_2019_v30n1_1_t0002.png 이미지

Table 3. NH3 decomposition conversion for various catalysts

SSONB2_2019_v30n1_1_t0003.png 이미지

참고문헌

  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.