Applied Chemistry for Engineering, Vol.21, No.5, 537-541, October, 2010
환원법에 의한 직접 메탄올 연료전지(DMFC)용 Pt-Sn/Carbon 전극제조
Synthesis of Pt-Sn/Carbon Electrodes by Reduction Method for Direct Methanol Fuel Cell
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초록
금속물질의 분산도를 높여주기 위해 열처리와 산처리를 수행한 carbon black에 다양한 비율의 Pt와 Sn을 담지 시킨 촉매를 환원법을 이용하여 합성하였다. Pt/Sn의 비율은 전구체 용액 내에서 상대적인 농도를 변화시켜 조절하였으며, Pt/Sn 비율에 따른 반응 특성을 조사하였다. XRD (X-ray Diffraction) 분석을 통해 합성된 촉매의 결정도를 확인하였고, XPS (X-ray Photoelectron Spectroscopy) 분석으로 Pt와 Sn의 산화가를 확인하였다. 합성된 촉매의 조성과 구조를 분석하기 위해 SEM (Scanning Electron Microscopy)-EDS (Energy Dispersive Spectroscopy) 분석과 TEM (Transmission Electron Microscopy) 분석을 수행하였다. 산소 환원 반응 특성은 0.5 M H2SO4 수용액에서 RDE (Rotating Disk Electrode)를 이용하여 조사하였으며, 산소환원 촉매활성은 Pt/Sn의 비율에 크게 의존함을 확인하였다. 합성한 전극의 메탄올 산화반응은 전기화학분석장치(Potentiostat ; Princeton applied research, VSP)를 이용하여 0.5 M CH3OH와 0.5 M H2SO4의 혼합수 용액에서 수행하였다. 메탄올 산화에 대한 전기화학적 촉매활성과 안정성을 평가한 결과 적절한 양의 Sn을 첨가한 촉매가 높은 촉매활성과 안정성을 나타냄을 확인하였다.
Pt-Sn with various ratios was supported on carbon black after pretreatment in an acidic solution by a reduction method. The Pt/Sn ratio was controlled by varying the concentration of each component in the solution, and the influence of the composition on the electrocatalytic activities was investigated. The crystallinity of the synthesized materials was investigated by XRD (X-ray Diffraction), and the oxidation states of both the platinum and tin were determined by XPS (X-ray Photoelectron Spectroscopy). SEM (Scanning Electron Microscopy)-EDS (Energy Dispersive Spectroscopy) was utilized to examine the morphology and composition of the synthesized electrode, and the particle size of the Pt-Sn was analyzed by TEM (Transmission Electron Microscopy). The electrocatalytic activity for oxygen reduction was evaluated in a 0.5 M H2SO4 solution using a rotating disk electrode system. The activity and stability were found to be strongly dependent on the electrode composition (Pt/Sn ratio). The catalytic activity and stability for methanol oxidation were also measured using cyclic voltammetry (CV) in a mixture of 0.5 M H2SO4 and 0.5 M CH3OH aqueous solution. The addition of proper amount of Sn was found to significantly improve both catalytic activity and stability for methanol oxidation.
- Oh SS, Kim GJ, J. Korean Ind. Eng. Chem., 18(5), 459 (2007)
- Voss S, Kollmann H, Kollmann W, J. Power Sources, 127(1-2), 93 (2004)
- Jeong KJ, Miesse CA, Choi JH, Lee J, Han J, Yoon SP, Nam SW, Lim TH, Lee TG, J. Power Sources, 168(1), 119 (2007)
- Wei ZD, Chan SH, J. Electroanal. Chem., 569(1), 23 (2004)
- Gurau B, Smotkin ES, J. Power Sources, 112(2), 339 (2002)
- Dimitrova P, Friedrich KA, Stimming U, Vogt B, Solid State Ion., 150(1-2), 115 (2002)
- Prabhuram J, Zhao TS, Wong CW, Guo JW, J. Power Sources, 134(1), 1 (2004)
- Radmilovic V, Richardson TJ, Chen SJ, Ross PN, J. Catal., 232(1), 199 (2005)
- Colmati F, Antolini E, Gonzalez ER, Appl. Catal. B: Environ., 73(1-2), 106 (2007)
- Prabhuram J, Zhao TS, Wong CW, Guo JW, J. Power Sources, 134(1), 1 (2004)
- Davis DJ, Kyriakou G, Lambert RM, J. Phys. Chem. B, 110(24), 11958 (2006)
- Xu JB, Zhao TS, Liang ZX, J. Power Sources, 185(2), 857 (2008)
- Kim JH, Choi SM, Nam SH, Seo MH, Choi SH, Kim WB, Appl. Catal. B: Environ., 82(1-2), 89 (2008)
- Neri G, Milone C, Galvagno S, Pijpers APJ, Schwank J, Appl. Catal. A: Gen., 227(1-2), 105 (2002)
- Damjanovic A, Genshaw MA, O’M. Bockris J, J. Chem. Phys., 45, 4057 (1966)
- Perez J, Tanaka AA, Gonzalez ER, Ticianelli EA, J. Electrochem. Soc., 141, 432 (1998)
- Maruyama J, Inaba M, Ogumi Z, J. Electroanal. Chem., 458(1-2), 175 (1998)