Anion-exchange membrane direct ethanol fuel cells: Status and perspective

Abstract

Direct ethanol fuel cells (DEFCs) are a promising carbon-neutral and sustainable power source for portable, mobile, and stationary applications. However, conventional DEFCs that use acid proton-exchange membranes (typically Nafion type) and platinum-based catalysts exhibit low performance (i.e., the state-of-the-art peak power density is 79.5 mW/cm² at 90°C). Anion-exchange membrane (AEM) DEFCs that use low-cost AEM and non-platinum catalysts have recently been demonstrated to yield a much better performance (i.e., the state-of-the-art peak power density is 160 mW/cm² at 80°C). This paper provides a comprehensive review of past research on the development of AEM DEFCs, including the aspects of catalysts, AEMs, and single-cell design and performance. Current and future research challenges are identified along with potential strategies to overcome them.

Key words： fuel cell; direct ethanol fuel cells; anion-exchange membrane; ethanol oxidation reaction; oxygen reduction reaction; cell performance

Acknowledgements

This work was supported by a grant from the Research Grants Council of the Hong Kong Special Administrative Region, China (Project No. 623709).

Fig.1Fig.2

T.S. Zhao is a Professor of Mechanical Engineering and the Director of Center for Sustainable Energy Technology at the Hong Kong University of Science & Technology (HKSUT). As an internationally renowned expert in energy technology, he presently focuses his research on fuel cells, multi-scale multiphase heat/mass transport with electrochemical reactions, and computational modeling. As of October 2010, he has published more than 150 papers in prestigious journals in the fields of energy science and engineering with SCI citations of more than 2850 times and H-index of 30. He has received a number of recognitions for his research and teaching, including the Bechtel Foundation Engineering Teaching Excellence Award at HKUST in 2004, the Overseas Distinguished Young Scholars Award by National Natural Science Foundation of China in 2006, Fellow of the American Society of Mechanical Engineers (ASME) in 2007, the Croucher Senior Fellowship award from the Croucher Foundation in 2008, and the Yangtze River Chair Professorship by the Chinese Ministry of Education in 2010. In the international community, Prof. Zhao serves as Editor-in-Chief of Advances in Fuel Cells, Series Editor, Energy & Environment (Royal Society of Chemistry), Asian Regional Editor of Applied Thermal Engineering, and as a member of the Editorial Board for more than 18 International Journals.

References

1 Prakash S, Kohl P A J. Performance of carbon dioxide vent for direct methanol fuel cells. Power Sources, 2009, 192(2): 429–434

2 Song S Q, Tsiakaras P. Recent progress in direct ethanol proton exchange membrane fuel cells (DE-PEMFCs). Appl Catal. B: Environ, 2006, 63(3,4): 187–193

3 Tu H C, Wang Y Y, Wan C C, Hsueh K L. Semi-empirical model to elucidate the effect of methanol crossover on direct methanol fuel cell. J Power Sources, 2006, 159(2): 1105–1114

4 Schultz T, Krewer U, Vidakovic T, Pfafferodt M, Christov M, Sundmacher K. Systematic analysis of the direct methanol fuel cell. J. Appl Electrochem, 2007, 37(1): 111–119

5 Scott K, Taama W M, Argyropoulos P, Sundmacher K. The impact of mass transport and methanol crossover on the direct methanol fuel cell. J Power Sources, 1999, 83(1,2): 204–216

6 Chetty R, Kundu S, Xia W, Bron M, Schuhmann W, Chirila V, Brandl W, Reinecke T, Muhler M. PtRu nanoparticles supported on nitrogen-doped multiwalled carbon nanotubes as catalyst for methanol electrooxidation. ElectrochimiActa, 2009, 54(17): 4208–4215

7 Zhao H B, Yang J, Li L, Li H, Wang J L, Zhang Y M. Effect of over-oxidation treatment of Pt-Co/polypyrrole-carbon nanotube catalysts on methanol oxidation. Int J Hydrogen Energy, 2009, 34 (9): 3908–3914

8 Song Y J, Han S B, Lee J M, Park K W. PtRu alloy nanostructure electrodes for methanol electrooxidation. J Alloy Compd, 2009, 473(1,2): 516–520

9 Han J H, Liu H T. Real time measurements of methanol crossover in a DMFC. J Power Sources, 2007, 164(1): 166–173

10 Heinzel A, Barragan V M. A review of the state-of-the-art of the methanol crossover in direct methanol fuel cells. J Power Sources, 1999, 84(1): 70–74

11 Ren X, Springer T E, Gottesfeld S. Water and Methanol uptakes in nafion membranes and membrane effects on direct methanol cell performance. J Electrochem Soc, 2000, 147(1): 92–98

12 Antolini E. Catalysts for direct ethanol fuel cells. J Power Sources, 2007, 170(1): 1–12

13 Fujiwara N, Friedrich K A, Stimming U. Ethanol oxidation on PtRu electrodes studied by differential electrochemical mass spectrometry. J Electroanal Chem, 1999, 472(2): 120–125

14 Pramanik H, Wragg A A, Basu S. Studies on operating parameters and cyclic voltammetry of a direct ethanol fuel cell. J Appl Electrochem, 2008, 38(9): 1321–1328

15 Zhou W J, Li W Z, Song S Q, Zhou Z H, Jiang L H, Sun G Q, Xin Q, Poulianitis K, Kontou S, Tsiakaras P. Bi- and tri-metallic Pt-based anode catalysts for direct ethanol fuel cells. J Power Sources, 2004, 131(1,2): 217–223

16 Song S Q, Zhou W J, Zhou Z H, Jiang L H, Sun G Q, Xin Q, Leonditis V, Kontou S, Tsiakaras P. Pt-based catalysts for direct ethanol fuel cellsInt J Hydrogen Energy, 2005, 30(9) : 995–1001

17 Colmenares L, Wang H, Yusys Z, Jiang L, Yan S, Sun G Q, Behm R J. Ethanol oxidation on novel, carbon supported Pt alloy catalysts—Model studies under defined diffusion conditions. Electrochim Acta, 2006, 52(1): 221–233

18 Lamy C, Rousseau S, Belgsir E M, Coutanceau C, Léger J M, Recent progress in the direct ethanol fuel cell: development of new platinum-tin electrocatalysts. Electrochim Acta, 2004, 49(22,23): 3901–3908

19 Bianchini C, Shen P K. Palladium-based electrocatalysts for alcohol oxidation in half cells and in direct alcohol fuel cells. Chem Rev, 2009, 109(9): 4183–4206

20 Antolini E, Gonzalez E R. Alkaline direct alcohol fuel cells, J Power Sources, 2010, 195(11): 3431–3450

21 Varcoe J R, Slade R C T. Prospects for alkaline anion-exchange membranes in low temperature fuel cells. Fuel Cells, 2005, 5(2): 187–200

22 Yu E H, Scott K, Reeve R W. electrochemical reduction of oxygen on carbon supported pt and pt/ru fuel cell electrodes in alkaline solutions. Fuel Cells, 2003, 3(4): 169–176

23 Xu J B, Zhao T S, Shen S Y, Li Y S. Stabilization of the palladium ethanol-oxidation electrocatalyst with alloyed goldInt J Hydrogen Energy, 2010, 35(13): 6490–6500

24 Rao V, Hariyanto, Cremers C, Stimming U. Investigation of the ethanol electro-oxidation in alkaline membrane electrode assembly by differential electrochemical mass spectrometry. Fuel Cells, 2007, 7(5): 417–423

25 Varcoe J R, Kizewski J P, Halepoto D M, Poynton S D, Slade R C T, Zhao F. Anion-Exchange Membranes. Encyclopedia of Electrochemical Power Sources, Amsterdam, 2009, 329–343

26 Wang Y, Li L, Hu L, Zhuang L, Lu J T, Xu B Q. A feasibility analysis for alkaline membrane direct methanol fuel cell: thermodynamic disadvantages versus kinetic advantages. Electrochem Commun, 2003, 5(8): 662–666

27 Yanagi H, Fukuta K. Anion Exchange Membrane and Ionomer for Alkaline Membrane Fuel Cells (AMFCs). ECS Trans, 2008, 16(2): 257–262

28 Agel E, Bouet J, Fauvarque J F. Characterization and use of anionic membranes for alkaline fuel cells. J Power Sources, 2001, 101(2): 267–274

29 Wan Y, Peppley B, Creber K A M, Bui V T, Halliop E. Quaternized-chitosan membranes for possible applications in alkaline fuel cells. J Power Sources, 2008, 185(1): 183–187

30 Xu T W, Liu Z M, Li Y, Yang W H. Preparation and characterization of Type II anion exchange membranes from poly(2,6-dimethyl-1,4-phenylene oxide) (PPO). J Membr Sci, 2008, 320(1,2): 232–239

31 Pandey A K, Goswami A, Sen D, Mazumder S, Childs R F. Formation and characterization of highly crosslinked anion-exchange membranes. J Membr Sci, 2003, 217(1,2): 117–130

32 Slade R C T, Varcoe J R. Investigations of conductivity in FEP-based radiation-grafted alkaline anion-exchange membranes. Solid State Ionics, 2005, 176(5,6): 585–597

33 Varcoe J R, Slade R C T, Yee E L H, Poynton S D, Driscoll D J, Apperley D C. Poly(ethylene-co-tetrafluoroethylene)-derived radiation-grafted anion-exchange membrane with properties specifically tailored for application in metal-cation-free alkaline polymer electrolyte fuel cells. Chem Mater, 2007, 19(10): 2686–2693

34 Varcoe J R, Slade R C T. An electron-beam-grafted ETFE alkaline anion-exchange membrane in metal-cation-free solid-state alkaline fuel cells. Electrochem Commun, 2006, 8(5): 839–843

35 Grew K N, Chu D, Chiu W K S. Ionic equilibrium and transport in the alkaline anion exchange membrane. J. Electrochem Soc, 2010, 157(8): B1024–B1032

36 Wan Y, Peppley B, Creber K A M, Bui V T. Anion-exchange membranes composed of quaternized-chitosan derivatives for alkaline fuel cells JPower Sources, 2010, 195(12): 3785–3793

37 Lu S F, Pan J, Huang A B, Zhuang L, Lu J T. Alkaline polymer electrolyte fuel cells completely free from noble metal catalysts. PNAS, 2008, 105(52): 20611–20614

38 Hibbs M R, Fujimoto C H, Cornelius C J. Synthesis and characterization of poly(phenylene)-based anion exchange membranes for alkaline fuel cells. Macromolecules, 2009, 42(21): 8316–8321

39 Wang G G, Weng Y M, Chu D, Xie D, Chen R R. Preparation of alkaline anion exchange membranes based on functional poly(ether-imide) polymers for potential fuel cell applications. J Membr Sci, 2009, 326(1): 4–8

40 Xiong Y, Liu Q L, Zhang Q G, Zhu A M. Synthesis and characterization of cross-linked quaternized poly(vinyl alcohol)/chitosan composite anion exchange membranes for fuel cells. J Power Sources, 2008, 183(2): 447–453

41 Wang E D, Zhao T S, Yang W W. Poly (vinyl alcohol)/3-(trimethylammonium) propyl-functionalized silica hybrid membranes for alkaline direct ethanol fuel cellsInt J Hydrogen Energy, 2010, 35(5): 2183–2189

42 Wu C M, Wu Y H, Luo J Y, Xu T W, Fu Y X. Anion exchange hybrid membranes from PVA and multi-alkoxy silicon copolymer tailored for diffusion dialysis process. J Membr Sci, 2010, 356(1,2): 96–104

43 Yang C C, Chiu S J, Lee K T, Chien W C, Lin C T, Huang C A. Study of poly(vinyl alcohol)/titanium oxide composite polymer membranes and their application on alkaline direct alcohol fuel cell. J Power Sources, 2008,184(1): 44–51

44 Lei L, Wang Y X. Quaternized polyethersulfone Cardo anion exchange membranes for direct methanol alkaline fuel cells. J Membr Sci, 2005, 262(1,2): 1–4

45 Salmon E, Guinot S, Godet M, Fauvarque J F. Structural characterization of new poly(ethylene oxide)-based alkaline solid polymer electrolytes. J Appl Polym Sci, 1997, 65(3): 601–607

46 Hou H Y, Sun G Q, He R H, Sun B Y, Jin W, Liu H, Xin Q. Alkali doped polybenzimidazole membrane for alkaline direct methanol fuel cellInt J Hydrogen Energy, 2008, 33(23): 7172–7176

47 Xiong Y, Liu Q L, Zeng Q H. Quaternized cardo polyetherketone anion exchange membrane for direct methanol alkaline fuel cells. J Power Sources, 2009, 193(2): 541–546

48 Stoica D, Ogier L, Akrour L, Alloin F, Fauvarque J F. Anionic membrane based on polyepichlorhydrin matrix for alkaline fuel cell: Synthesis, physical and electrochemical properties. Electrochim Acta, 2007, 53(4): 1596–1603

49 Wu L, Xu T W. Improving anion exchange membranes for DMAFCs by inter-crosslinking CPPO/BPPO blends. J Membr. Sci, 2008, 322(2): 286–292

50 Varcoe J R, Beillard M, Halepoto D M, Kizewski J P, Poynton S D, Slade R C T. Membrane and Electrode Materials for Alkaline Membrane Fuel Cells. ECS Trans., 2008, 16(2): 1819–1834

51 Park J S, Park S H, Yim S D, Yoon Y G, Lee W Y, Kim C S. Performance of solid alkaline fuel cells employing anion-exchange membranes JPower Sources, 2008, 178 (2) 620–626

52 Fukuta K, Inoue H, Watanabe S, Yanagi H. In-situ Observation of CO2 through the Self-purging in Alkaline Membrane Fuel Cell (AMFC). ECS Trans,2009, 19(31): 23–27

53 Adams L A, Poynton S D, Tamain C, Slade R C T, Varcoe J R. A carbon dioxide tolerant aqueous-electrolyte-free anion-exchange membrane alkaline fuel cell. ChemSusChem, 2008, 1(1,2): 79–81

54 Matsui Y, Saito M, Tasaka A, Inaba M. Influence of carbon dioxide on the performance of anion-exchange membrane fuel cells. ECS Trans., 2010, 25(13) 105–110

55 Einsla B R, Chempath S, Pratt L R, Boncella J M, Rau J, Macomber C, Pivovar B S. Stability of cations for anion exchange membrane fuel cells. ECS Trans, 2007, 11(1): 1173–1180

56 Xiong Y, Liu Q L, Zhu A M, Huang S M, Zeng Q H. Performance of organic-inorganic hybrid anion-exchange membranes for alkaline direct methanol fuel cells. J Power Sources, 2009, 186(2): 328–333

57 Wu Y H, Wu C M, Li Y, Xu T W, Fu Y X. PVA–silica anion-exchange hybrid membranes prepared through a copolymer crosslinking agent. J Membr Sci, 2010, 350(1,2): 322–332

58 Yang C C, Chiu S J, Chien W C, Chiu S S. Quaternized poly(vinyl alcohol)/alumina composite polymer membranes for alkaline direct methanol fuel cells. J Power Sources, 2010, 195(8): 2212–2219

59 Yang C C. Synthesis and characterization of the cross-linked PVA/TiO₂ composite polymer membrane for alkaline DMFC. J Membr. Sci, 2007, 288(1,2): 51–60

60 Wu Y H, Wu C M, Xu T W, Yu F, Fu Y X. Novel anion-exchange organic–inorganic hybrid membranes: Preparation and characterizations for potential use in fuel cells. J Membr Sci, 2008, 321(2): 299–308

61 Varcoe J R, Slade R C T, Yee E L H, Poynton S D, Driscoll D J. Investigations into the ex situ methanol, ethanol and ethylene glycol permeabilities of alkaline polymer electrolyte membranes. J Power Sources, 2007, 173(1): 194–199

62 Xing B, Savadogo O. Hydrogen/oxygen polymer electrolyte membrane fuel cells (PEMFCs) based on alkaline-doped polybenzimidazole (PBI). Electrochem. Commun, 2000, 2(10): 697–702

63 Fu J, Qiao J L, Lv H, Ma J X, Yuan X Z, Wang H J. Alkali doped poly (vinyl alcohol) (PVA) for anion-exchange membrane fuel cells: Ionic conductivity, chemical stability and FT-IR characterizations. ECS Trans, 2010, 25(13): 15–23

64 Leykin A Y, Shkrebko O A, Tarasevich M R. Ethanol crossover through alkali-doped polybenzimidazole membrane. J Membr. Sci, 2009, 328(1,2): 86–89

65 Hou H Y, Sun G Q, He R H, Wu Z M, Sun B Y. Alkali doped polybenzimidazole membrane for high performance alkaline direct ethanol fuel cell. J Power Sources, 2008, 182(1): 95–99

66 Varcoe €J €R. €Investigations €of €the€ ex€ situ€ ionic€ conductivities€ at 30°C of metal-cation-free quaternary ammonium alkaline anion-exchange membranes in static atmospheres of different relative humidities. Phys Chem Chem Phys, 2007, 9(12): 1479–1486

67 Li Y S, Zhao T S, Yang W W. Measurements of water uptake and transport properties in anion-exchange membranes. Int J Hydrogen Energy, 2010, 35(11): 5656–5665

68 Stoica D, Alloin F, Marais S, Langevin D, Chappey C, Judeinstein P. Polyepichlorydrine membrane for alkaline fuel cell: Sorption and conduction properties. J Phys Chem B, 2008, 112(39): 12338–12346

69 Abuin G C, Nonjola P, Franceschini E A, Izraelevitch F H, Mathe M K, Corti H R. Characterization of an anionic-exchange membranes for direct methanol alkaline fuel cellsInt J Hydrogen Energy, 2010, 35(11): 5849–5854

70 Zawodzinski T A, Springer T E, Davey J, Jestel R, Lopez C, Valerio J, Gottesfeld S. A comparative study of water uptake by and transport through ionomeric fuel cell membranes. J Electrochem Soc, 1993, 140(7): 1981–1985

71 Choi P, Datta R. Sorption in proton-exchange membranes. J Electrochem Soc, 2003,150(12): E601–E607

72 Colmati F, Antolini E, Gonzalez E R. Effect of temperature on the mechanism of ethanol oxidation on carbon supported Pt, PtRu and Pt₃Sn electrocatalysts. J Power Sources, 2006, 157(1): 98–103

73 Li H Q, Sun G Q, Cao L, Jiang L H, Xin Q. Comparison of different promotion effect of PtRu/C and PtSn/C electrocatalysts for ethanol electro-oxidation. Electrochim Acta, 2007, 52(24): 6622–6629

74 Shen Q M, Min Q H, Shi J J, Jiang L P, Zhang J R, Hou W H, Zhu J J. Morphology-controlled synthesis of palladium nanostructures by sonoelectrochemical method and their application in direct alcohol oxidation. J Phys Chem C, 2009, 113(4): 1267–1273

75 Wang X G, Wang W M, Qi Z, Zhao C C, Ji H, Zhang Z H. High catalytic activity of ultrafine nanoporous palladium for electro-oxidation of methanol, ethanol, and formic acid. Electrochem Commun, 2009, 11(10): 1896–1899

76 Ksar F, Surendran G, Ramos L, Keita B, Nadjo L, Prouzet E, Beaunier P, Hagège A, Audonet F, Remita H. Palladium nanowires synthesized in hexagonal mesophases: application in ethanol electrooxidation. Chem Mater, 2009, 21(8): 1612–1617

77 Xu C W, Shen P K, Liu Y L. Ethanol electrooxidation on Pt/C and Pd/C catalysts promoted with oxide. J Power Sources, 2007,164(2): 527–531

78 Hu F P, Chen C L, Wang Z Y, Wei G Y. Mechanistic study of ethanol oxidation on Pd-NiO/C electrocatalyst. Electrochim Acta, 2006, 52(3): 1087–1091

79 Chu D B, Wang J, Wang S X, Zha L G, He J G, Hou Y Y, Yan Y G, Lin H S, Tian Z W. High activity of Pd–In₂O₃/CNTs electrocatalyst for electro-oxidation of ethanol. Catal Commun, 2009, 10(6): 955–958

80 He Q G, Chen W, Mukerjee S, Chen S W, Laufek F. Carbon-supported PdM (M = Au and Sn) nanocatalysts for the electrooxidation of ethanol in high pH media. J Power Sources, 2009,187(2): 298–304

81 Zhu L D, Zhao T S, Xu J B, Liang Z X. Preparation and characterization of carbon-supported sub-monolayer palladium decorated gold nanoparticles for the electro-oxidation of ethanol in alkaline media. J Power Sources, 2009, 187(1): 80–84

82 Ksar F, Ramos L, Keita B, Nadjo L, Beaunier P, Remita H. bimetallic palladium-gold nanostructures: application in ethanol oxidation. Chem Mater, 2009, 21(15): 3677–3683

83 Liu Z L, Zhao B, Guo C L, Sun Y J, Xu F G, Yang H B, Li Z. Novel hybrid electrocatalyst with enhanced performance in alkaline media: hollow Au/Pd core/shell nanostructures with a raspberry surfaceJ Phys Chem C, 2009, 113(38): 16766–16711

84 Nguyen S T, Law H M, Nguyen H T, Kristian N, Wang S, Chan S H, Wang X. Enhancement effect of Ag for Pd/C towards the ethanol electro-oxidation in alkaline media. Appl Catal B, 2009, 91(1,2): 507–515

85 Wang Y, Nguyen T S, Liu X W, Wang X. Novel palladium–lead (Pd–Pb/C) bimetallic catalysts for electrooxidation of ethanol in alkaline media. J Power Sources, 2010,195(9): 2619–2622

86 Chen Y G, Zhuang L, Lu J T. Non-Pt anode catalysts for alkaline direct alcohol fuel cells. Chin. J Catal, 2007, 28(10): 870–874

87 Jou L S, Chang J K, Twhang T J, Sun I W. Electrodeposition of palladium-copper€films€from€1-ethyl-3-methylimidazolium€chloride-tetrafluoroborate ionic liquid on indium tin oxide electrodes. J Electrochem Soc, 2009,156(6): D193–D197

88 Singh R N, Singh A, Anindita. Electrocatalytic activity of binary and ternary composite films of Pd, MWCNT, and Ni for ethanol electro-oxidation in alkaline solutions. Carbon, 2009, 47(1): 271–278

89 Shen S Y, Zhao T S, Xu J B, Li Y S. Synthesis of PdNi catalysts for the oxidation of ethanol in alkaline direct ethanol fuel cells. J Power Sources, 2010, 195(4): 1001–1006

90 Qiu C C, Shang R, Y F Xie, Bu Y R, Li C Y, Ma H Y. Electrocatalytic activity of bimetallic Pd–Ni thin films towards the oxidation of methanol and ethanol. Mater Chem Phys, 2010, 120(2,3): 323–330

91 Bambagioni V, Bianchini C, Filippi J, Oberhauser W, Marchionni A, Vizza F, Psaro R, Sordelli L, Foresti M L, Innocenti M. Ethanol oxidation on electrocatalysts obtained by spontaneous deposition of palladium onto nickel-zinc materials. ChemSusChem, 2009, 2(1): 99–112

92 Zheng H T, Li Y L, Chen S X, Shen P K. Effect of support on the activity of Pd electrocatalyst for ethanol oxidation. J Power Sources, 2006, 163(1): 371–375

93 Xu C W, Chen L Q, Shen P K, Liu Y L. Methanol and ethanol electrooxidation on Pt and Pd supported on carbon microspheres in alkaline media. Electrochem. Commun, 2007, 9(5): 997–1001

94 Yuan D S, Xu C W, Liu Y L, Tan S Z, Wang X, Wei Z D, Shen P K. Synthesis of coin-like hollow carbon and performance as Pd catalyst support for methanol electrooxidation. Electrochem Commun, 2007, 9(10): 2473–2478

95 Hu F P, Shen P K. Ethanol oxidation on hexagonal tungsten carbide single nanocrystal-supported Pd electrocatalyst. J Power Sources, 2007,173(2): 877–881

96 Hu F P, Cui G F, Wei Z D, Shen P K. Improved kinetics of ethanol oxidation on Pd catalysts supported on tungsten carbides/carbon nanotubesElectrochem Commun, 2008, 10(9): 1303–1306

97 Wang Z Y, Hu F P, Shen P K. Carbonized porous anodic alumina as electrocatalyst support for alcohol oxidation. ElectrochemCommun, 2006, 8(11): 1764–1768

98 Hu F P, Ding F W, Song S Q, Shen P K. Pd electrocatalyst supported on carbonized TiO₂ nanotube for ethanol oxidation. J Power Sources, 2006, 163(1): 415–419

99 El-Shafei A A, Elhafeez A M, Mostafa H A. Ethanol oxidation at metal–zeolite-modified electrodes in alkaline medium. Part 2: palladium–zeolite-modified graphite electrode. J Solid State Electrochem, 2010, 14(2): 185–190

100 Pandey R K, Lakshminarayanan V. Enhanced electrocatalytic activity of Pd-Dispersed 3,4-polyethylenedioxythiophene film in hydrogen evolution and ethanol electro-oxidation reactions. J Phys Chem C, 2010, 114(18): 8507–8514

101 Pandey R K, Lakshminarayanan V. Electro-oxidation of formic acid, methanol, and ethanol on electrodeposited Pd-polyaniline nanofiber films in acidic and alkaline medium. J Phys Chem C, 2009, 113(52): 21596–21603

102 Su L, Jia W Z, Schempf A, Ding Y, Lei Y. free-standing palladium/polyamide 6 nanofibers for electrooxidation of alcohols in alkaline medium. J Phys Chem C, 2009, 113(36): 16174–16180

103 Zhou W J, Song S Q, Li W Z, Sun G Q, Xin Q, Kontou S, Poulianitis K, Tsiakaras P. Pt-based anode catalysts for direct ethanol fuel cells. Solid State Ionics, 2004, 175(1–4) : 797–803

104 Mann J, Yao N, Bocarsly A B. Characterization and analysis of new catalysts for a direct ethanol fuel cell. Langmuir, 2006, 22(25): 10432–10436

105 Liang Z X, Zhao T S, Xu J B, Zhu L D. Mechanism study of the ethanol oxidation reaction on palladium in alkaline media. Electrochim Acta, 2009, 54(8): 2203–2208

106 Cui G F, Song S Q, Shen P K, Kowal A, Bianchini C. First-principles considerations on catalytic activity of Pd toward ethanol oxidation. J Phys Chem C, 2009, 113(35): 15639–15642

107 Fang X, Wang L Q, Shen P K, Cui G F, Bianchini C. An in situ Fourier transform infrared spectroelectrochemical study on ethanol electrooxidation on Pd in alkaline solution. J Power Sources, 2010, 195(5): 1375–1378

108 Zhou Z Y, Wang Q, Lin J L, Tian N, Sun S G. In situ FTIR spectroscopic studies of electrooxidation of ethanol on Pd electrode in alkaline media. Electrochim Acta, 2010 (in press)

109 Bambagioni V, Bianchini C, Marchionni A, Filippi J, Vizza F, Teddy J, Serp P, Zhiani M. Pd and Pt-Ru anode electrocatalysts supported on multi-walled carbon nanotubes and their use in passive and active direct alcohol fuel cells with an anion-exchange membrane (alcohol=methanol, ethanol, glycerol). J Power Sources, 2009, 190(2): 241–251

110 Markovic N, Gasteiger H. Kinetics of oxygen reduction on Pt(Hkl) electrodes–Implications for the crystallite size effect with supported pt electrocatalysts. J Electrochem Soc, 1997, 144(5): 1591–1597

111 Blizanac B B, Ross P N, Marković N M. Oxygen reduction on silver low-index single-crystal surfaces in alkaline solution: Rotating ring disk_Ag(hkl) studies. J Phys Chem B, 2006, 110(10): 4735–4741

112 Blizanac B B, Ross P N, Marković N M. Oxygen electroreduction on Ag(1 1 1): The pH effect. Electrochim Acta, 2007, 52(6): 2264–2271

113 Geniès L, Faure R, Durand R. Electrochemical reduction of oxygen on platinum nanoparticles in alkaline media. Electrochim Acta, 1998, 44(8,9): 1317–1327

114 Xu J B, Zhao T S, Li Y S, Yang W W. Synthesis and characterization of the Au-modified Pd cathode catalyst for alkaline direct ethanol fuel cells. Int J Hydrogen Energy, 2010, 35(18): 9693–9700

115 Xiong L F, Manthiram A. Influence of atomic ordering on the electrocatalytic activity of Pt–Co alloys in alkaline electrolyte and proton exchange membrane fuel cellsJ Mater Chem, 2004, 14: 1454–1460

116 Demarconnay L, Coutanceau C, Léger J M. Study of the oxygen electroreduction at nanostructured PtBi catalysts in alkaline medium. Electrochim Acta, 2008, 53(8): 3232–3241

117 Gülzow E, Wagner N, Schulze M. preparation of gas diffusion electrodes with silver catalysts for alkaline fuel cells. Fuel Cells, 2003, 3(1,2): 67–72

118 Demarconnay L, Coutanceau C, Léger J M. Electroreduction of dioxygen (ORR) in alkaline medium on Ag/C and Pt/C nanostructured catalysts- effect of the presence of methanol. Electrochim Acta, 2004, 49(25): 4513–4521

119 Guo J S, Hsu A, Chu D, Chen R R. Improving oxygen reduction reaction activities on carbon-supported Ag nanoparticles in alkaline solutions. J Phys Chem C, 2010, 114(10): 4324–4330

120 Mao L Q, Zhang D, Sotomura T, Nakatsu K. Mechanistic study of the reduction of oxygen in air electrode with manganese oxides as electrocatalysts. Electrochim Acta, 2003, 48(8): 1015–1021

121 Calegaro M L, Lima F H B, Ticianelli E A. Oxygen reduction reaction on nanosized manganese oxide particles dispersed on carbon in alkaline solutions, J Power Sources, 2006,158(1): 735–739

122 Fukuda M, Iida C, Nakayama M. One-step through-mask electrodeposition of a porous structure composed of manganese oxide nanosheets with electrocatalytic activity for oxygen reduction. Mater Res Bull, 2009, 44(6): 1323–1327

123 Hermann V, Dutriat D, Müller S, Comninellis C. Mechanistic Studies of oxygen reduction at La0.6Ca0.4CoO3-activated carbon electrodes in a channel flow cell. Electrochim. Acta, 2000, 46(2,3): 365–372

124 Nissinen T, Valo T, Gasik M, Rantanen J, Lampinen M. Microwave synthesis of catalyst spinel MnCo₂O₄ for alkaline fuel cell. J Power Sources, 2002, 106(1,2): 109–115

125 Chang Y M, Wu P W, Eu C Y, Hsieh Y C. Synthesis of La_0.6Ca_0.4Co_0.8Ir_0.2O₃ perovskite for bi-functional catalysis in an alkaline electrolyte. J Power Sources, 2009, 189(2): 1003–1007

126 Restovic A, Ríos E, Barbato S, Ortiz J, Gautier J L. Oxygen reduction in alkaline medium at thin Mn_xCo_3-xO₄ (0≤x≤1) spinel films prepared by spray pyrolysis. Effect of oxide cation composition on the reaction kinetics. J Electroanal Chem, 2002, 522(2): 141–151

127 Koninck M D, Poirier S C, Marsan B. Electrochemical characterization for the oxygen reduction reaction. J Electrochem Soc, 2007, 154(4): A381–A388

128 Ríos E, Abarca S, Daccarett P, Cong H N, Martel D, Marco J F, Gancedo J R, Gautier J L. Electrocatalysis of oxygen reduction on Cu_xMn_3-xO₄ (1.0<x<1.4) spinel particles/polypyrrol composite electrodes. Int J Hydrogen Energy, 2008, 33(19): 4945–4954

129 Gojković S L, Gupta S, Savinell R F. Heat-treated iron(III) tetramethoxyphenyl porphyrin chloride supported on high-area carbon as an electrocatalyst for oxygen reduction: Part II. Kinetics of oxygen reduction. J Electroanal Chem, 1999, 462 (1) : 63–72

130 Mocchi C, Trasatti S. Composite electrocatalysts for molecular O₂ reduction in electrochemical power sources. J Mol Catal A, 2003, 204–205: 713–720

131 Tributsch H, Koslowski U I, Dorbandt I. Experimental and theoretical modeling of Fe-, Co-, Cu-, Mn-based electrocatalysts for oxygen reduction. ElectrochimActa, 2008, 53(5): 2198–2209

132 Lima F H B, Ticianelli E A. Oxygen electrocatalysis on ultra-thin porous coating rotating ring/disk platinum and platinum-cobalt electrodes in alkaline media. ElectrochimActa, 2004, 49(24): 4091–4099

133 Lima F H B, Zhang J, Shao M H, Sasaki K, Vukmirovic M B, Ticianelli E A, Adzic R R. Catalytic activity–d-band center correlation for the O₂ reduction reaction on platinum in alkaline solutions. J Phys Chem C, 2007, 111(1): 404–410

134 Coutanceau C, Demarconnay L, Lamy C, Léger J M. Development of electrocatalysts for solid alkaline fuel cell (SAFC). J Power Sources, 2006, 156(1): 14–19

135 Chatenet M, Bultel L G, Aurousseau M, Durand R, Andolfatto F. Oxygen reduction on silver catalysts in solutions containing various concentrations of sodium hydroxide-comparison with platinum. J Appl Electrochem, 2002, 32(10): 1131–1140

136 Furuva N, Aikawa H. Comparative study of oxygen cathodes loaded with Ag and Pt catalysts in chlor-alkali membrane cells. Electrochim Acta, 2000, 45(25,26): 4251–4256

137 Wagner N, Schulze M, Gülzow E. Long term investigations of silver cathodes for alkaline fuel cells. J Power Sources, 2004, 127(1,2): 264–272

138 Okajima K, Nabekura K, Kondoh T, Sudoh M. Degradation evaluation of gas-diffusion electrodes for oxygen-depolarization in chloralkali membrane cell. J Electrochem Soc, 2005, 152(8): D117–D120

139 Lee H K, Shim J P, Shim M J, Kim S W, Lee J S. Oxygen reduction behavior with silver alloy catalyst in alkaline media. Mater Chem Phys, 1996, 45(3): 238–242

140 Lima F H B, Castro J F R, Ticianelli E A. Silver-cobalt bimetallic particles for oxygen reduction in alkaline media. J Power Sources, 2006, 161(2): 806–812

141 Meng H, Shen P K. Novel Pt-free catalyst for oxygen electroreduction. Electrochem Commun, 2006, 8(4): 588–594

142 Li Y S, Zhao T S, Liang Z X. Performance of alkaline electrolyte-membrane-based direct ethanol fuel cells. J Power Sources, 2009, 187(2): 387–392

143 Fujiwara N, Siroma Z, Yamazaki S, Ioroi T, Senoh H, Yasuda K. Direct ethanol fuel cells using an anion exchange membrane. J Power Sources, 2008, 185(2): 621–626

144 Bianchini C, Bambagioni V, Filippi J, Marchionni A, Vizza F, Bert P, Tampucci A. Selective oxidation of ethanol to acetic acid in highly efficient polymer electrolyte membrane-direct ethanol fuel cells. Electrochem Commun, 2009, 11(5): 1077–1080

145 Jiang L H, Sun G Q, Sun S G, Liu J G, Tang S H, Li H Q, Zhou B, Xin Q. Structure and chemical composition of supported Pt-Sn electrocatalysts for ethanol oxidation. ElectrochimActa, 2005, 50(27): 5384–5389

146 Modestov A D, Tarasevich M R, Leykin A Y, Filimonov V Y. MEA for alkaline direct ethanol fuel cell with alkali doped PBI membrane and non-platinum electrodes. J Power Sources, 2009, 188(2): 502–506

147 Li Y S, Zhao T S, Liang Z X. Effect of polymer binders in anode catalyst layer on performance of alkaline direct ethanol fuel cells. J Power Sources, 2009, 190(2): 223–229

148 Miyazaki K, Abe T, Nishio K, Nakanishi H, Ogumi Z. Use of layered double hydroxides to improve the triple phase boundary in anion-exchange membrane fuel cells. J Power Sources, 2010, 195(19): 6500–6503

149 Li Y S, Zhao T S, Chen R. Cathode flooding behaviour in alkaline direct ethanol fuel cells. J Power Sources, 2011, 196(1): 133–139