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2007HF-PABW1 Fuel cells Ingrid Hantschk/Hans Fibi PABW April 2007 Uniwersytet Mikolaja Kopernika IPUC TFPC 29274-IC-2-2005-1-AT-ERASMUS-IPUC-19.

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Presentation on theme: "2007HF-PABW1 Fuel cells Ingrid Hantschk/Hans Fibi PABW April 2007 Uniwersytet Mikolaja Kopernika IPUC TFPC 29274-IC-2-2005-1-AT-ERASMUS-IPUC-19."— Presentation transcript:

1 2007HF-PABW1 Fuel cells Ingrid Hantschk/Hans Fibi PABW April 2007 Uniwersytet Mikolaja Kopernika IPUC TFPC IC AT-ERASMUS-IPUC-19

2 2007HF-PABW2 Electrolyses of water Electrolysis of water by Johann Georg Ritter 1800 The electrolysis of water for getting hydrogen was and is the base of creating a fuel cell. The two electrodes end underneath the vessels for hydrogen and oxygen. O2O2 H2H2

3 2007HF-PABW3 Electrolysis of water rebuilt water with sodium carbonate + - Proof for: H 2 detonating gas O 2 glowing piece of wood ignites Electrolysis experiment (Ritter, 1800):

4 2007HF-PABW4 Concentrated sodium carbonate Electrolyses of water Na 2 CO 3 The electrodes are plastic syringes with knitting- needles glued into them.

5 2007HF-PABW5 Electrolyses of water In the year 1880 the British chemist William Nicholson proofed that bubbles of hydrogen and oxygen appear when you put the contacts of a battery into water. Hofmann‘s „Extractionapparatus“ Voltage used for extraction: U = 1,23 V H 2 O and 0,1m H 2 SO 4

6 2007HF-PABW6 Electrolysis of water

7 2007HF-PABW7 Synthesis of water detonating gas 2H 2 + O 2  2 H 2 O proof for H 2 proof for O 2

8 2007HF-PABW8 Electrolyses of water Acid system: Voltage used for extraction: U = 1,23 V Katode-reaction: 2 H + + 2e -  H 2 Anode-reaction: H 2 O  2 H + + ½ O 2 + 2e - Sum-reaction: H 2 O  H 2 + ½ O 2 2 H 2 O  2 H 2 + O 2 Alcaline system: Voltage used for extraction: U = 1,7 – 2,3 V Katode-reaction:2 H 2 O + 2e -  2OH - + H 2 Anode-reaction:2 OH -  H 2 O + ½ O e - Sum-reaction:H 2 O  H 2 + ½ O 2 2 H 2 O  2 H 2 + O 2

9 2007HF-PABW9 Electrolysis of water – Electrolysis of sulfuric-acid cathode-reaction: 2 H + + 2e -  H 2 anode-reaction: 2 HSO 4 -  S 2 O H + + 2e - H 2 S 2 O 8 + H 2 O  H 2 SO 5 + H 2 SO 4 H 2 SO 5 + H 2 O  H 2 SO 4 + H 2 O 2 2 H 2 O 2  2 H 2 O + O 2

10 2007HF-PABW10 Historical fuel cell Hofmann-Apparatus: If there are H 2 and O 2 atoms then there is electricity between the poles.

11 2007HF-PABW11 Elektrolyseur water storage O2O2 H2H2 Diaphragm Pure water is used for the electrolysis whilst using the right diaphragm (membrane).

12 2007HF-PABW12 Elektrolyseur Pure water is used for the electrolysis whilst using the right diaphragm (membran). Cathode  Reduction 2H 2 O + 2e -  2OH - + H 2 Anode  Oxidation 2OH -  H 2 O + ½ O 2 + 2e - Redox-Process locally seperated

13 2007HF-PABW13 Elektrolyseur Extraction of water – Membranelectrolysis Diaphragm („NAFION“-Membran): ions should pass through gas should not pass through Voltage used for extraction > 1,23 DCV Membranelectrolysis with acid Membranelectrolysis with alcalite Electrolysis with high temperature

14 2007HF-PABW14 Fuel cell oxidating matter: hydrogen methanole matter for oxidation: oxygen

15 2007HF-PABW15 Fuel cell - Elektrolyseur Fuel cell: voluntary process at U 0 = 1,40 V Oxidation: 2H 2  4H e - Reduction: O 2 + 4e - + 2H 2 O  4 OH - Sum: 2H 2 + O 2  2H 2 O + energy Elektrolysis cell: forced process bei U 0 > 1,40 V Reduction: 4H e -  2H 2 Oxidation: 4 OH -  O 2 + 4e - + 2H 2 O Sum: 2 H 2 O + energy  2H 2 + O 2

16 2007HF-PABW16 Fuel cell katode elektrolyte anode oxygen hydrogen + - waterwarmth

17 2007HF-PABW17 Schematic fuel cell Taken from: Univ.Prof. Dr. Kordesch, TU Graz

18 2007HF-PABW18 Schematic fuel cell H 2 + ½ O 2  H 2 O with  G = kJ/mol U = 1,23 V technical U ~ 0,9 V  G: free reaction‘s enthalpie  H: reaction‘s temperature n: number of transmitted electrons (n = 2) F: Faraday-Constant (96487 C/mol) E: Voltage

19 2007HF-PABW19 Fuel cell (alcalite) Elektrolyte alcalite: Anode-reaction:H OH -  2 H 2 O + 2 e - Katode-reaction:½ O 2 + H 2 O + 2 e -  2 OH - Both reactions run katalytic. Sum-reaction:H 2 + ½ O 2  H 2 O 2e - H2H2 ½ O 2 KOH 2OH - H2OH2O2H 2 O H2OH2O cathode, porous 6 mol KOH anode, porous

20 2007HF-PABW20 Fuel cell (acid) Using a acidly electrolytreults following reactions: Anode-reaction:H 2  2 H e - Katode-reaction:1/2 O H e -  H 2 O Sum-reaction:H 2 + 1/2 O 2  H 2 O Fuel cell with acid 2e - anodekatode H2H2 O2O2 2H + H2OH2O H 2 SO 4 Ni-Electrode

21 2007HF-PABW21

22 2007HF-PABW22 Fuel cell modell for self-structure solargenerator 4 cells serial connected sunlight or artificial light switch: charge- discharge solarengine as a user model of a led-akkumulator

23 2007HF-PABW23 Brennstoffzelle Selbstbau alcalite fuel cell: KOH conc. / 2 coalplates lightbulb 6V/0,3W as user K K...cuvette with coalplates as a model of a fuel cell


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