화학공학소재연구정보센터
Journal of the Korean Industrial and Engineering Chemistry, Vol.12, No.7, 773-778, November, 2001
불소 전해 탄소전극 특성에 미치는 성형압의 영향
Molding Pressure Effects on Electrode Properties of Carbon Anode for Fluorine Electrolysis
E-mail:
초록
충진제인 petroleum cokes와 결합제인 coal tar pitch를 주원료로 성형압을 변화시켜 불소 전해용 탄소전극을 제조한 후 성형압에 따른 탄소전극의 물리적, 기계적 특성과 전기적 특성을 조사하고, 특히 기공상태와 전극특성의 상호관계를 조사하였다. 1 mM [Fe(CN)6](3-)/[Fe(CN)6](4-)의 이온이 용해되어 있는 0.5 M K2SO4 용액에서 cyclic voltammogram 거동을 통한 전기적 특성 조사에서 성형압 2000 kg/cm(2)으로 제조된 전극의 경우가 가장 양호한 전극 특성을 나타냈다. 전기화학적 특성은 성형압에 의해 나타난 전극표면의 기공상태에 의존하였으며, 이러한 기공의 크기 및 분포를 통하여 실질적으로 전극의 비표면적의 변화상태를 알 수 있었다. 또한 KF·2HF 용액의 불소 전해제조를 통해 전극특성을 조사하여 성형압 2000 kg/cm(2)에서 평균 22.780 A/dm(2)의 높은 임계전류밀도를 얻었다.
Carbon anodes for electrolytic production of fluorine were fabricated using petroleum coke as the filler and coal tar pitch as the binder. The effects of molding pressures on the mechanical strength and electrode properties were investigated. The relationship between physical properties of pores and electrode properties were also investigated. Evaluation of electrochemical properties was performed by cyclic voltammogram in 0.5 M K2SO4 solution with 1 mM [Fe(CN)6](3-)/[Fe(CN)6](4-) redox couple. It was revealed that the carbon anode, fabricated at the molding pressure of 2000 kg/cm(2) had superior electrode properties than one that was fabricated at other pressures. The electrode properties of a carbon anode were found to be related to the size and distribution of pore. Corresponding change of effective internal surface area was estimated and evaluated. Electrochemical behaviour of the carbon anodes were also estimated for the fluorine generation in the molten KF·2HF electrolyte. The carbon anode molded at 2000 kg/cm(2) showed high critical current density of 22.780 A/dm(2).
  1. Nakakima T, "Fluorine-Carbon and Fluoride-Carbon materials," p. 251, Marcel Dekker, Inc. (1995)
  2. Childs WV, Bauer GL, J. Electrochem. Soc., 142(7), 2286 (1995) 
  3. Bai L, Conway BE, J. Appl. Electrochem., 18, 839 (1988) 
  4. Groult H, Devilliers D, Vogler M, Chemla M, J. Appl. Electrochem., 24(9), 870 (1994) 
  5. Miyazaki K, Hagio T, Kobayashi K, J. Mater. Sci., 16, 752 (1981) 
  6. Ogawa I, Yoshida H, Kobayashi K, J. Mater. Sci., 16, 1281 (1981)
  7. Bermejo J, Granda M, Menendez R, Garcia R, Fuel, 76, 179 (1997) 
  8. Oh HJ, Lee JH, Lee YH, Koo YS, J. Korean Chem. Soc., 40, 308 (1996)
  9. Nicholson RS, Anal. Chem., 36, 706 (1964) 
  10. Delahay P, "New Instrumental Methods in Electrochemistry," p. 119, Interscience Publishers Inc. (1954)
  11. Deakin MR, J. Electroanal. Chem., 182, 113 (1985) 
  12. Wightman RM, J. Electrochem. Soc., 1578 (1984) 
  13. Nakajima T, Ogawa T, Watanabe N, J. Fluor. Chem., 40, 407 (1988) 
  14. Watanabe N, Inoue M, Yoshizawa S, Denki Kagaku, 31, 698 (1963)
  15. Bard AJ, "Encyclopedia of Electrochemistry of the Elements," p. 103, Marcel Dekker, Inc. (1976)