화학적 합성법에 의한 금속수소화물의 제조 및 수소화 속도론적 연구

이윤성; 오재완; 문성식; 남기석

Journal of the Korean Industrial and Engineering Chemistry, Vol.9, No.2, 255-260, April, 1998

Export Citation

화학적 합성법에 의한 금속수소화물의 제조 및 수소화 속도론적 연구

Preparation of Metal Hydrides Using Chemical Synthesis and Hydriding Kinetics

이윤성, 오재완, 문성식, 남기석

초록

금속수소화물 LaNi₅와 LaNi_4.5Al_0.5을 화학적 합성법으로 제조하여, 합성된 금속수소화물의 물성을 다양한 방법으로 확인하였다. LaNi₅와 LaNi_4.5Al_0.5은 2회 정도 수소화/탈수소화 반응을 시키면 활성화되었으며, 압력-농도-온도 곡선을 측정한 결과 각각 6개와 5.5개의 수소원자가 저장되었다. LaNi_4.5Al_0.5의 경우 수소화 반응속도를 초기속도법으로 구한 결과 비반응 수축핵모델이 잘 적용되었으며, 수소화반응의 율속단계는 LaNi_4.5Al_0.5의 표면에서 수소분자의 해리화학흡착임을 알 수 있었다. LaNi_4.5Al_0.5의 수소화 반응 활성화에너지는 9.506kcal/mol-H₂이었으며, 반응속도식은 273∼343K와 P₀-P_eq=0.25∼0.66atm의 범위에서 아래와 같이 표시되었다. dX/dt=4.636(P₀-P_eq)exp(-9506/RT)

Metal hydrides, LaNi₅ and LaNi_4.5Al_0.5, were prepared using chemical synthetic method, and their physical properties were examined using various analytic techniques such as TGA, XRD, SEM and EDX. The activation of the chemically prepared LaNi₅ and LaNi_4.5Al_0.5 was achieved by two hydriding/dehydriding cycles only. The miasurements of P-C-T curves revealed that 6 and 5.5 hydrogen atoms were stored in LaNi₅ and LaNi_4.5Al_0.5, respectively. The hydriding reaction rated for LaNi_4.5Al_0.5 were measured by the method of initial rates. It was found that the shrinking unreacted core model could be applied for the analysis of hydriding kinetics of LaNi₅. The rate controlling step of this reaction was the dissociative chemisorption of hydrogen molecules on the surface of LaNi₅. The activation energy was 9.506kcal/mol-H₂. The rates measured in the temperature range from 273 to 343K and in pressure difference (P₀-P_eq) range form 0.25 to 0.66atm could be expressed as the following equation ; dX/dt=4.636(P₀-P_eq)exp(-9506/RT)

[References]

Pangborn J, Scott M, Sharer J, Int. J. Hydrog. Energy, 2, 431 (1977)
Huang CJ, Tang KK, Kelly JH, Berger BJ, Int. J. Hydrog. Energy, 4, 287 (1979)
Osumi Y, Chem. Econ. Eng. Rev., 16, 12 (1984)
Genshi W, Xianglong W, Deying S, Panwen S, Int. J. Hydrog. Energy, 14, 45 (1989)
Fogler HS, Elements of Chemical Reaction Engineering, 2nd ed., Chap. 5, Prentice-Hall Int., Inc. (1992)
Nahm KS, Kim WY, Hong SP, Lee WY, Int. J. Hydrog. Energy, 17, 333 (1992)
Nahm KS, Ph.D. Dissertation, Seoul National Univ., Seoul, Korea (1986)
Bronoel G, Sarradin J, Percheron-Guegan A, Achard JC, Schlapbach L, Int. J. Hydrog. Energy, 1, 251 (1976)
Genshi W, Daxin Z, Deying S, Xianglong W, Panwen S, Proc. Int. Conf. on Rare Earth Development and Applications, 2, 1063 (1985)
Percheron-Guegan A, Achard JC, Sarradin J, Bronoel G, Proc. Int. Symp. on Hydrides for Energy Storage, 1, 485 (1978)
Nahm KS, Jung WB, Lee WY, Int. J. Hydrog. Energy, 15, 635 (1990)
Jung WB, Nahm KS, Lee WY, Int. J. Hydrog. Energy, 15, 641 (1990)

[1] Pangborn J, Scott M, Sharer J, Int. J. Hydrog. Energy, 2, 431 (1977)

[2] Huang CJ, Tang KK, Kelly JH, Berger BJ, Int. J. Hydrog. Energy, 4, 287 (1979)

[3] Osumi Y, Chem. Econ. Eng. Rev., 16, 12 (1984)

[4] Genshi W, Xianglong W, Deying S, Panwen S, Int. J. Hydrog. Energy, 14, 45 (1989)

[5] Fogler HS, Elements of Chemical Reaction Engineering, 2nd ed., Chap. 5, Prentice-Hall Int., Inc. (1992)

[6] Nahm KS, Kim WY, Hong SP, Lee WY, Int. J. Hydrog. Energy, 17, 333 (1992)

[7] Nahm KS, Ph.D. Dissertation, Seoul National Univ., Seoul, Korea (1986)

[8] Bronoel G, Sarradin J, Percheron-Guegan A, Achard JC, Schlapbach L, Int. J. Hydrog. Energy, 1, 251 (1976)

[9] Genshi W, Daxin Z, Deying S, Xianglong W, Panwen S, Proc. Int. Conf. on Rare Earth Development and Applications, 2, 1063 (1985)

[10] Percheron-Guegan A, Achard JC, Sarradin J, Bronoel G, Proc. Int. Symp. on Hydrides for Energy Storage, 1, 485 (1978)

[11] Nahm KS, Jung WB, Lee WY, Int. J. Hydrog. Energy, 15, 635 (1990)

[12] Jung WB, Nahm KS, Lee WY, Int. J. Hydrog. Energy, 15, 641 (1990)