15 1 No.1 Vol Journal of Chemical Engineering of Chinese Universities Feb Teflon-C Nafion 80 0.

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1 15 1 No.1 Vol Journal of Chemical Engineering of Chinese Universities Feb : (2001) * 1 2, 1, 1, 1, 2 2, ( ) : Pt-Ru/C,, Teflon-C Nafion 0.6mg cm -2 Teflon-C Nafion 0.3 mg cm mg cm V 36mA cm mA cm -2 9cm 2 / 0.285W 0.7V 0.407A / 0.635V 0.252A 0.160W TM911.4 A 1 (Direct Fuel Cell DMFC) [1] DMFC CH 3 OH+H 2 O CO 2 +6H + +6e - 3/2O 2 +6H + +6e - CH 3 OH+3/2O 2 3H 2 O CO 2 +2H 2 O DMFC [2] DMFC DMFC DMFC M BALDAUF [3] SCOTT [6 7 8] D H JUNG [9] A K SHUKLA [10 M HOGARTH [4] A S ARICO [5] K 11] DMFC M BALDAUF 77W DMFC L 100 DMFC DMFC Pt-Ru/C Teflon-C Nafion DMFC ; (980520) (1969-) :

2 [12] 2.2 [13] 2.3 PTFE 1 Oxygen or air Carbon dioxide Oxygen or air Carbon dioxide Oxygen or air Carbon dioxide water Fig.1 +water 10 water 1 +water water DMFC Schematic representation of a DMFC three cells stack 1. end plate 2. silica gel plate 3. current collection plate 4. single polar plate 5. sealer +water 6. carbon paper diffusion layer 7. cathode catalyst layer 8.Nafion membrane 9. anode catalyst layer 10. bipolar plate DMFC ( ) PTFE A B solution Fig.2 Pump Cathode polar plate Cathode Nafion membrane Anode Anode polar plate A P V Resistance Oxygen in Oxygen out Water out Outgas and water out 2 Schematic testing diagrams of liquid-feed DMFC

3 M 0.6mL min -1 20mL min MPa 80 ( ) 3.2, Pt 0.1mg cm mg cm mg cm mg cm mgPt cm -2 [14] 3.3 Teflon-C Teflon-C PTFE Teflon-C 0.1 mg cm mg cm mg cm mg cm -2 Teflon-C Teflon-C PTFE PTFE

4 Nafion Nafion Nafion Nafion Nafion [14] Nafion 6 Nafion Nafion 0.5mg cm -2 Nafion Nafion Nafion Nafion [15] Nafion [15] M 0.2MPa 8(a) (b) 9(a) (b) V 0.285W 45mA cm A

5 W 0.635V 28mA cm A 4 (1) Pt-Ru/C 0.6mgPt cm -2 Teflon-C Nafion 0.3mg cm mg cm -2 (2) 0.3V 22.5mA cm ma cm -2 (3) 80 9cm 2 / 0.285W 0.7V 0.405A / 0.635V 0.252A 0.160W [1] JIANG Qi-zhong ( ) MA Zi-feng ( ) HUANG Bi-chun, et al ( ). Application of instrument analysis technique in direct methanol fuel cell ( )[J]. Journal of Spectroscopy Laboratory ( ), 2000, 17 (2): 129. [2] Wasmus S, Kuver A. oxidation and direct methanol fuel cells: a selective review [J]. J of Electroanal Chem, 1999, 146: [3] Baldauf M, Preidel W. Status of the development of a direct methanol fuel cell [J]. J of Power Sources. 1999, 84: [4] Hogarth M, Christensen P, Hamnett A, et al. The design and construction of high-performance direct methanol fuel cells.1 Liquidfeed systems [J]. J of Power Sources, 1997, 69: [5] Arico A S, Creti P, Antonucci P L, et al. Optimization of operationg parameters of a direct methanol fuel cell and physico-chemical investigation of catalyst-electrolyte interface [J]. Electrochimica Acta. 1998, 43(24): [6] Scott K, Taama W M, Argyropoulos P, et al..the impact of mass transport and methanol crossover on the direct methanol fuel cell [J]. J of Power Sources. 1999, 83: [7] Scott K, Taama W M, Argyropoulos P. Material aspects of the liquid feed direct methanol fuel cell [J]. J App.Electrochem, 1998, 28:

6 [8] Scott K, Taama W M, Argyropoulos P. Engineering aspects of the direct methanol fuel cell system [J]. J of Power Sources. 1999, 79: [9] Jung D H, Lee C H, Kim C S, et al. Performance of a direct polymer electrolyte fuel cell [J]. J of Power Sources, 1998, 71: [10] Shukla A K, Christensen P A, Dickinson A J, et al. Liquid-feed solid polymer electrolyte direct methanol fuel cell operation at near ambient conditions [J]. J of Power Sources, 1998, 76: [11] Shukla A K, Ravikumar M K, Neergat M, et al. A 5 W liquid-feed solid-polymer-electrolyte direct methanol fuel cell stack with stainless steel [J]. J App Electrochem, 1999, 29: [12] JIANG Qi-zhong ( ), ZHOU Jin-xin ( ) MA Zi-feng et al ( ). Study on electrochemical performance and electrocatalyst for direct methanol electro-oxidation ( )[J]. Journal of Power Sources Technique ( ), 2000, 24(4): 218. [13] JIANG Qi-zhong ( ) MA Zi-feng ( ) LIN Wei-ming ( ). Study on performance of liquid-feed direct methanol fuel cell ( ) [J]. New Energy Sources ), 2000, 22(7): 5. [14] XU Hong-feng ( ), YI Bao-lian ( ), HAN Ming ( ). Effect of electrode structures on the performance of proton exchange membrane fuel cell ( ) [J]. Journal of Power Source Technique( ), 1998, 22(4): 163. [15] GE Shan-hai ( ), YI Bao-lian ( ), XU Hong-feng et al ( ). Study of proton-exchange membrane fuel cells(pemfc) ( ) [J]. Electrochemistry ( ), 1998, 4(3): 299. Study on Performance of Liquid-feed Direct Fuel Cell JIANG Qi-zhong 1 2, MA Zi-feng 1, LIU Zhen-tai 1, ZHOU Jin-xin 1, HUANG Bi-chun 2, LIN Wei-ming 2 (1. Department of Chemical Engineering, Shanghai Jiaotong University, Shangsai , China; 2. Department of Chemical Engineering, South China University of Technology, Guangzhou , China) Abstract: Using Pt-Ru/C catalyst as anode and cathode catalysts, the membrane electrode assembly was prepared and single direct methanol fuel cell system was installed. The effect of preparation methods of diffusion layer, catalyst content, Teflon-C content and Nafion content in catalyst layer on single cell performance were studied. The results showed that the performance was better in the diffusion layer prepared by paste than by spray; the best catalyst content was 0.6mg cm -2 while that of Teflon-C, Nafion was 0.3 mg cm -2 and 0.5 mg cm -2 respectively When the working temperature was 80 and output voltage was 0.3V the output current density was 36mA cm -2 with oxygen as cathode oxidant and that was 22.5mA cm -2 with air as oxidant. The maximum power of liquid-feed direct methanol/oxygen three-cell stack, where available MEA area was 9 mm 2, was 0.285W and its output voltage and current was 0.7V and 0.407A respectively. When air replaced oxygen as oxidant, the stack s voltage was 0.635V, its current was 0.252A and its maximum power was 0.160W. Key words: membrane electrode assembly(mea); direct methanol fuel cell; single cell; stack