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Bio-inspired Constructs,
Biomemitic Catalysts,
Methanogenesis
Fuel Cells, Borohydrides, Catalysts, Ionic Liquids,
Si-Electroplating
II-IV-V Semiconductors, Nanowires, Metal Complexes
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WHY the Borohydride Hydrogen Storage for a Fuel Cell ?

Membraneless Fuel Cell Architectures
  • Fuel-cell power system package projected to give > 4x application  life of a battery-pack of the same size if can achieve:
    — Energy dense of H2 storage (Energy density > 2200 Wh/liter or kilogram)
  • Low temperature hydrogen generation is compatible with hand-carried portables.
  • Safe: aqueous alkaline borohydride H2 storage solution is nontoxic, nonflammable and a liquid borohydride storage cartridge leaks slowly whereas a pressurized tank of H2 is hazardous & H2 lost nearly instantly.
  • Fuel cell system is cost competitive with rechargeable batteries at < $10/Watt.

Issues Borohydride Hydrogen Storage & Generation

Need to:
  • optimize hydrogen-generating catalyst/support
  • maximize energy density…. maximize solubility of reactants and products in solution

H2 Generation by Hydrolysis of Borohydrides
h2 generation

Sodium Borohydride Hydrolysis
  • Hydride on borohydride reduces proton from water
  • Rate of hydrolysis decreases as pH increases, due to decreasing concentration of proton
Accelerating Borohydride Hydrolysis
  • LiBH4 hydrolysis is rapid at all pH. Why?
  • NaBH4 hydrolysis is slow in base, fast in acid. Why?
  • NaBH4 hydrolysis is rapid at all pH in the presence of Ru! Why?

H2 Generation by Catalytic Hydrolysis of Sodium Borohydride

ionic liquids
  • Li+, Ruo attract H2O and BH4- forming stable intermediates on the Ru (or Li)
  • Stabilizing the activated complex between H2O and BH4 lowering the barrier to hydrolysis
  • Rate of hydrogen generation increases at ROOM TEMPERATURE

catalytic
Hydrogen Generator
hydrogen generator
Expected to flood chamber and generate gas and collect at top
Only utilized Catalyst on bottom
So evaluated catalyst activity next!

Fuel mixture composition: 30 wt% NaBH4, 4.3 wt% NaOH, 67 wt% H2O Provides 2250 Watt-hour per liter of mixture at 100% conversion efficiency Mass of Ru estimated at 52mg!

Catalyst Characterization
catalyst characterization
H2 generator integrated to Fuel Cell and Fuel Cartridge
catalyst characterization
Current Research
  • Identify products of hydrolysis in the presence of glycol
  • Determine the mechanism of solubility increase (true solution, colloidal dispersion, etc.)
  • Evaluate the effectiveness of other polyalcohols for increasing the solubility of hydrolysis by-products.
  • Determine the highest borohydride solution concentration practical for a room temperature fuel cell system.

For more information, please, contact professor Don Gervasio

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