Journal of Hydrogen and New Energy (한국수소및신에너지학회논문집)

The Korean Hydrogen and New Energy Society (한국수소및신에너지학회)
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Electrochemical Oxidation of Hydrogen at Palladium Electrode

팔라디움 전극에서의 전기화학적 수소산화반응

  • Oh, M.H. (Dept. of Chem. Eng., Hong Ik University) ;
  • Paik, C.H. (Div. of Chem. Eng., KIST) ;
  • Cho, B.W. (Div. of Chem. Eng., KIST) ;
  • Yun, K.S. (Div. of Chem. Eng., KIST) ;
  • Min, B.C. (Dept. of Chem. Eng., Hong Ik University) ;
  • Ju, J.B. (Dept. of Chem. Eng., Hong Ik University) ;
  • Sohn, T.W. (Dept. of Chem. Eng., Hong Ik University)
  • 오미혜 (홍익대학교 화학공학과) ;
  • 백지홈 (한국과학기술연구원 화공연구부) ;
  • 조병원 (한국과학기술연구원 화공연구부) ;
  • 윤경석 (한국과학기술연구원 화공연구부) ;
  • 민병철 (홍익대학교 화학공학과) ;
  • 주재백 (홍익대학교 화학공학과) ;
  • 손태원 (홍익대학교 화학공학과)
  • Published : 1996.06.30
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Abstract

Electrochemical oxidation of hydrogen on PdOx and Pd electrodes were investigated in aqueous 30% KOH solution at different temperatures and hydrogen concentrations(partial pressures). Anodic reaction by hydrogen on PdOx electrode was mainly due to the oxidation of adsorbed hydrogen at -0.8V~-0.5V(vs. Hg/HgO). For Pd electrode, the anodic reaction was participated by the adsorbed hydrogen on surface, as well as by the metal hydride formed from direct reaction between Pd and hydrogen at -0.5V~0.0V(vs. Hg/HgO). With the increase of hydrogen concentration the charge transfer resistance decreased and the exchange current increased. The transfer coefficient of PdOx and Pd electrodes were found to be 0.78 and 0.72 respectively, which shows the superior reactivity of Pd electrode. The activation energies of PdOx and Pd electrodes decreased with the increase of overpotential and were found to be 23.9~20.3 kJ/mole and 7.2~3.0kJ/mole, respectively.

PdOx 전극, Pd전극에서의 전기화학적 수소산화반응 특성을 30% KOH용액에서 온도와 수소농도를 변화시키면서 조사하였다. PdOx전극에서는 -0.8~-0.5V(vs. Hg/HgO)에서 전극 표면에 흡착된 수소의 산화반응이 주로 나타났고, Pd전극에서는 전극 표면에 흡착된 수소의 산화반응 뿐만 아니라 -0.5~0.0V(vs. Hg/HgO)에서 Pd과 수소가 직접 반응하여 형성된 금속수소화물이 산화되는 반응이 나타냈다. 두 전극 모두 수소농도의 증가에 따라 전하전달저항은 감소하였고, 교환전류는 증가하였다. PdOx 전극과 Pd전극의 경우 전달계수는 각각 0.78과 0.72로 Pd전극에서의 반응성이 우수하였다. 활성화에너지는 과전압이 증가할때 감소하였으며 PdOx 전극인 경우 23.9~20.3 KJ/mole, Pd전극인 경우 7.2~3.0KJ/mole로 나타났다.

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