1. Fuel Cells Device that produces electricity from external supplies of fuel and oxidant. Types of Fuel cells 1)Proton Exchange membrane Fuel Cell (PEMFC) 2)Direct Methanol 3)Solid oxide 4)Phosphoric acid 5)Alkaline 6)Molten carbonate

2. Proton Exchange membrane Fuel Cell (PEMFC) Design & Operation: Anode Reactions:2H 2 => 4H+ + 4e- Cathode Reactions:O 2 + 4H+ + 4e- => 2 H 2 O Overall Cell Reactions:2H 2 + O2 => 2 H 2 O Platinum: Anode & Cathode Operating temperature: about 80 0 C Membrane: Nafion, Polybenzimidazole (PBI)

3. Why PEMFC? 1)Higher power density (About 10 times greater than other fuel cells) 2)Lower cost 3)Instant startup 4)It is tiny, so easy to handle 5)Solid polymer membrane allows low pressure fuel & high pressure air on other side 6)Operates on pure hydrogen as well as reformed hydrocarbon fuels. Few drawbacks: 1)Platinum anode gets poisoned by CO in fuel 2)Operates at temp. < 100 0 C 3)Water management issues 4)Water & air crossover to anode through membrane 5)Less proton mobility through membrane

4. Future work Study of polymer membranes and issues related to PEMFC