Portable Hydrogen Generation

Motivation

  • Determine cost, safety, energy density, and overall feasibility of using ammonia borane in portable power generation applications
  • Develop low-cost, portable systems that can deliver on-demand hydrogen to drive a fuel cell as a direct alternative to batteries
    DoE targets comparison
    System comparison to DoE Targets for Portable Applications
    Aeropak System
    R&D to develop high-performance energy storage systems (Aeropak system shown as baseline)













Materials and Techniques

  • Ammonia borane (AB) hydrolysis (~9 wt.% hydrogen)
    • Reaction initiated with water addition
    • Suppresses toxic borazines vapors formed when AB is thermally decomposed
    • Challenge in eliminating the ammonia gas produced (compatibility with a proton exchange membrane fuel cell)
    • SEM Images
    SEM images of catalysts used, from left to right, Amberlyst-15 (as-received), Amberlyst-15 (ball-milled), and 20% Platinum / 80% Carbon
  • Characterization of catalyzed hydrolysis reaction (see: Ammonia Borane &: Sodium Borohydride)
    • Proton exchange resin used as a catalyst
    • Comparisons to traditional metal catalyst
  • Material Processing
    • Platinum black and activated carbon mixed via ball milling
    • Amberlyst – 15: ball milled separately to a similar particle size

Experimental Setup

Score Distribution
Experimental setup for AB hydrolysis reactions
  • Test the aspects of decomposition reaction that relate to portable operation with a PEM fuel cell
  • Control of the water delivery, and reaction environment
  • Measurements of temperature, pH, gas production rate, and gas purity

Experimental Results

FTIR Results
FTIR results
  • Gas Purity & Kinetics Studies:
    • Objective: determine activation energies and gas compatibility with PEM fuel cells
    • Gas chromatography used for hydrogen concentration
    • FTIR used to identify contaminate species
    • Amberlyst-15 eliminates ammonia production from AB hydrolysis and reduces activation energy by factor of ~5 compared to Pt/C catalyst

Accomplishments/Highlights

  • Decomposed ammonia borane via catalyzed hydrolysis
  • Tested gas purity and compatibility with PEM-fuel cells
  • Characterized hydrolysis reaction kinetics of AB using various catalysts

Multimedia


    Hydrolysis of AB with Amberlyst-15. Yield: 95% of theoretical, Reaction duration: 10 seconds, Exotherm: 5°C

    Hydrolysis of AB with Pt/C. Yield: 85% of theoretical, Reaction duration: 3 minutes, Exotherm: 20°C















People

PI

Dr. Timothée Pourpoint, Associate Professor, Purdue University

Researchers

Jason Gabl, Research Engineer, Purdue University

loading