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1、第三章 直接醇类燃料电池第一节阳离子交换膜醇类燃料电池第二节阴离子交换膜醇类燃料电池第三节甲醇工业的发展第二节阴离子交换膜醇类燃料电池研究背景工作原理及研究进展结论与展望Fuel cellChem. Energy(H2,CH3OH,N2H4,Zn)Electro.EnergyElectrocatalystEquipmentHeat energy kinetic energy研究背景甲醇，乙醇，乙二醇等小分子醇类的优点：比能量密度高(Neat Methanol:5000wh/L, 6000wh/Kg)液体燃料，易输运储存启动快(NO more waitingwaitingwaiting to r
2、e-charge!)环境友好（CO2，H2O）来源广泛（可利用现有的燃料供应系统）DMFCDAFC研究热点Direct Alcohol Fuel Cell Direct Methanol Fuel Cell 研究背景PEMPt,PtRu Pt酸性条件下：动力学反应速度慢（阳极）甲醇渗透（阴极）催化剂CO中毒严重膜价格昂贵（Nafion mem.）阳极:CH3OH+H2OCO2+6H+6e-阴极:3/2O2+6H+6e-3H2O总反应:CH3OH+3/2O2CO2+2H2O碱性条件下阴离子膜醇类燃料电池碱性条件下工作原理：KOH工作原理简图工作流程及MEA结构图Schematic represe
3、ntation of a direct alcohols fuel cell using an anion exchange membrane.工艺流程图阴离子膜介绍之一Anion-exchange membrane (AHA) of ammoniumtype wassuplied by Tokuyama Co.,JapanTetraalkyl ammonium group (四烷基季铵类) as fixed cation group bonded to polyolefin (聚烯烃)backbone chainThickness of 240mNafion ll7: 0.910.93meq
4、.g-10.20.05S cm-1183mhigh ionic conductivity 0.010.02 S cm-1Z.OgumiI et. Electrochemistry 2002,70,980阴离子膜介绍之二Morgane-ADP Solvay SA BelgiumE.H. Yu, K. Scott / Journal of Power Sources 137 (2004) 248256交联氟化聚合物其它阴离子膜介绍AEMs produced using PVDF聚偏二氟乙烯and FEP聚全氟乙丙烯base polymersPVDF, CH2CF2nFEP, CF2CF2nCF(C
5、F3)CF2mVBC，vinylbenzyl chloride (苯乙烯基氯化物)电导率0.02 S cm-1厚度50100mTimothy N. Danks, Robert C. T. Slade* and John R. VarcoeJ. Mater. Chem., 2002, 12, 33713373乙酰乙酸基丙烯酸乙酯其它阴离子膜介绍聚砜树酯其它阴离子膜介绍bslope of the linear regression of ln (/S cm-1) vs.(1000/T)/K-1plotsR8.3144J K-1mol-1Robert C.T. Slade, John R. Varc
6、oe*Solid State Ionics 176 (2005) 585597Meq/ganion exchange capacity“离子交换容量”，即每克干树脂或每毫升湿树脂所能交换的离子的毫克当量数，meq/g(干)或meq/mL(湿)；当离子为一价时，毫克当量数即是毫克分子数(对二价或多价离子，前者为后者乘离子价数)。Koji Matsuoka,Takeshi Abea,Zempachi Ogumia，,Journal of Power Sources 150 (2005) 2731MEA preparation0.2 mM H2PtCl6solution510 mM NaBH4sol
7、ution碱性条件下甲醇电氧化Cyclic voltammograms for the oxidation of 0.3 M CH3OH on the Pt(110)surface in three different alkaline solutions () and the correspondingbasic curves (- - -). Sweep rate: 50 mV s1; T=22C. A.V. Tripkovic, K. Dj. Popovic, J.D. Momcilovic, D.M. Drazic,Electrochim. Acta 44 (1998) 1135.甲醇
8、电氧化A.V. Tripkovic, K. Dj. Popovic, J.D. Momcilovic, D.M. Drazic,J. Electroanal. Chem. 448 (1998) 173.该机理的提出是基于将HCOad&OHad是中间产物,甲酸盐是稳定的主要产物Pt(100)甲醇氧化反应机理The rate determining step is most likely to be the oxidation of the active intermediate /CHO i.e.,step (7).On platinum, the bonding of chemisorbed
9、intermediates appears weakerthan in acidic media leading to more efficient electrooxidation.E. Hao Yu et al. / Journal of Electroanalytical Chemistry 547 (2003) 17 /24不同条件下醇类电氧化比较K.Matsuoka,T.Abe,Z.Ogumi et. Fuel cells,2(2002),35.沉积Pt在Ti载体上做工作电极，比较峰电流密度可知，EG在KOH条件下的最高，表现出最高的反应活性，有可能成为最理想的燃料（碱性条件下）K2
10、CO3KOHH2SO45木糖醇4赤藻糖醇3丙三醇2乙二醇1甲醇甲醇的放电性能E.H. Yu, K. Scott / Journal of Power Sources 137 (2004) 248256Catalyst：Pt/C（both）Membrace：Morgane ADPMEA制备：热压法Eileen Hao Yu *, Keith ScottElectrochemistry Communications 6 (2004) 361365The platinised Ti mesh showed high catalyticactivity,and gave stable fuel cel
11、l performance.The electrodeprovides a high surface area in the catalyst layer and offers lower mass transport resistance.不同催化剂的甲醇放电性能Cell tests at 60 , air pressure 1 bar, 2 M MeOH, 1 M NaOH with flow rate of 60.6 ml min)-1.E. H. YU* and K. SCOTT，Journal of Applied Electrochemistry (2005) 35:9196甲醇和
12、乙二醇的放电性能electrolyte：An OH-1form anion exchange membrane（AHA)Catalyst：Pt/C(E-TEK),(anode-5mg/cm2Pt,cathod-1mg/cm2Pt)MEA制备:室温压合（140kg/cm2，3min）Ethylene glycol&methanol : l mol/L,1mol/LKOH,50ml/min，O2,50ml/min9.2mW/cm25.5mW/cm2Z.Ogumi,K,Mabuoka,S.Chiba,M.Mabuoka,Y.Iriyama,T.Abe,M.Inaba,Electrochemistry
13、 12(2002),980-983不同小分子醇类放电性能OCP=0.8VP=9.8mW/cm2Cell voltage curves and Power density curves for alkaline direct alcohol fuel cells using polyhydric alcohols. Anode: PtRu/C, 50ml/min1M alcohol+1M KOHCathode: Pt/C, 50ml/min O2FC Temperature: 323 K. The open circuit voltages of the cells using methanol
14、 and polyhydric alcohols were almost identical at about 800mV.Koji Matsuoka,Takeshi Abea,Zempachi Ogumia，,Journal of Power Sources 150 (2005) 2731廉价催化剂的应用EG has low activity on Ag/C（cathode）High Concentration of ethylene glycol can improve the performance of the anodeCell voltage curves for alkaline
15、 alcohol direct fuel cells using15M ethylene glycol Concentration of ethylene glycol. Anode: PtRu/C; cathode: Ag/C (closed symbol) or Pt/C (open symbol); temperature: 323 K.Koji Matsuoka,Takeshi Abea,Zempachi Ogumia，,Journal of Power Sources 150 (2005) 2731结论与展望碱性条件下醇类有一定的发展空间：1.醇类和氧的反应活性高，开路电压高2.醇渗透率低，乙二醇表现出最好的活性3.廉价金属催化剂和廉价膜得到应用4.催化剂的CO中毒情况相对较弱有待深入的研究课题1.研制导OH-速率高、低阻抗、抗高温的阴离子膜2.催化剂的筛选工作3. CO2的影响不可忽视参考文献1) Z.Ogumi,K,Mabuoka,S.Chiba,M.Mabuoka,Y.Iriyama,T.Abe,M.Inaba,Electrochemistry12(2002),980-9832) E.H. Yu, K. Scott , Journal of Power Sources 137 (2004) 2482563) Timothy N. Danks,
