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62 Cards in this Set
- Front
- Back
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Operating temp of SOFC is |
700-1000C |
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Advantages of SOFC are |
high efficiency, solid electrolyte |
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A disadvantage of SOFC is |
high temperature corrosion |
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disadvantages of PEMFC are |
expensive catalyst, sensitive to fuel impurities |
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In PEMFC the electrodes are separated by |
cation exchange membrane |
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The membrane thickness in PEMFC is usually around |
fifty micrometers |
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In H2/O2 PEMFC the catalyst is usually |
Pt |
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Which is the fuel used in DMFC? |
methanol aqueous solution |
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An advantage of the methanol as fuel in DMFC is |
storage and transportation |
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In AFC the electro-catalyst can be made from |
metal oxides and Ag |
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AFC is intolerant to |
CO2 |
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In PAFC the ion-conducting electrolyte is |
H3PO4 |
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In PAFC the ionic conductivity is provided by |
H+ |
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The operating temperature of PAFC is around |
190C |
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The operating temperature of MCFC is around |
650C |
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A disadvantage of MCFC is |
durability |
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SOFC systems exist in |
two configurations |
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In SOFC the ion conductivity is provided by |
)2- ions |
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In SOFC the efficiency of converting fuel to electricty is around |
50-60 |
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The temperature range which is not covered by any of the fuel cell technologies is |
250-600C |
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In SOFC the ion-conducting electrolyte is |
YSZ |
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How many phases are in intimate contact at the PEMFC cathode at 120C and 1 bar |
3 |
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The main components of a membrane electrode assembly (MEA) in PEMFC are |
membrane, electrodes and gas diffusion layers |
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In PEMFC the bipolar plates |
collect electrical current, connect the cathode of one cell to to the anode of another cell |
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The nafion resistivity |
decrases with increasing temperature |
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The well-known comercial membrane for PEMFC is |
Nafion |
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The first property of a PENFC membrane to be tested is |
proton conductivity and gas permeability |
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Generally a higher loading of Pt catalyst in PEMFC leads to |
higher cell performance |
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In PEMFC the electrochemical reactions take place |
at the three-phase boundary |
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In PEMFC the gas diffusion layer is usually made from |
carbon cloth and carbon paper |
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The required property for a bipolar plate is |
niether low electrical conductivity or high weight |
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The catalyst load in PEMEC should be |
larger than in PEMFC |
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The SOFC is |
most sulfur resistant fuel cell |
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Typical material for the SOFC electrolye is |
YSZ |
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The common cathode materials for SOFC is |
LSM |
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The tubular SOFC interconnect can be made from |
lathanum chromite and metal alloy |
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Generally the ohmic slope in SOFC is |
smaller than in PEMFC |
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The theoretical and experimental OCP in SOFC is |
almost the same |
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Using the CRC handbook data, calculate the open circuit potential E, of CO/Air SOFC at temperature of 1000K and 1 bar assuming that the partial pressure of CO, CO2 and air is .5 bar |
.965 V |
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In PEMFC the bipolar plates can be made from |
graphite and a coated metal alloy |
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Using the CRC Handbook data, calculate the standard cell potential difference, Eo, of CO/O2 SOFC at temperature of 726.8C and 1 bar |
1.014V |
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The common feature among alkaline, phosphorric acid, and molten carbonate fuel cell is that |
all use a liquid electrolyte |
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An advantage of MCFC is |
fuel flexibility and high total efficiency |
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A disadvantage of PAFC is |
expensive catalyst |
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AFC can be used for |
underwater vehicles and spacecrafts |
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In AFC, the ionic charge transfer is provided by |
OH- ions |
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Electrocatalyst in alkaline fuel cell can be made from |
Ni and metal oxides |
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The operating temperature of PAFC is |
150 -200C |
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The advantage of PAFC is |
improved tolerance to impurities |
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In MCFC with H2 as fuel, CO2 is |
reactant at the cathode and product at the anode |
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The operating temperature of MCFC is |
600-700C |
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The MCFC electrolyte is |
lithium-potassium carbonate mixture |
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The MCFC cathode is |
NiO |
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A two chamber MFC uses |
a proton exchange membrane |
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In MFC, the bacteria play the role of |
catalyst |
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In MFC, the CO2 is produced at |
the anode |
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The calculated standard OCP of MFC using acetate ion as fuel is around |
1.0V |
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In MFC, the power density mainly depends on |
structure of the cell |
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The power output of MCF is |
much less than a PEMFC or DMFC |
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For producing hydrogen |
MFC should be modified to be a MEC |
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Bacteria in MFC should |
reduce the anodic overpotential |
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Using the CRC handbook data, calculate the standard OCP of a MFC at 50C and 1 bar if the total electrochemical reaction is CH3COO-(aq)+2O2(g)=CO2(g)+HCO3-(aq)+H2O(l) |
1.096 V |
