1 / 14

Hydrogen Storage in Ti-doped NaAlH4

Hydrogen Storage in Ti-doped NaAlH4. William Gempel. National Hydrogen Initiative. President Bush has proposed $1.2 billion over the next five years to support a new Hydrogen Fuel Initiative. Elements of a Hydrogen Energy Infrastructure. Production Delivery Storage

emily
Download Presentation

Hydrogen Storage in Ti-doped NaAlH4

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Hydrogen Storagein Ti-doped NaAlH4 William Gempel

  2. National Hydrogen Initiative President Bush has proposed $1.2 billion over the next five years to support a new Hydrogen Fuel Initiative.

  3. Elements of a Hydrogen Energy Infrastructure • Production • Delivery • Storage • Conversion • Applications

  4. Hydrogen Storage Methods • High Pressure Tanks • Liquid Hydrogen • Carbon Nanotube Surface Absorbtion • MgH2 • NaAlH4

  5. Comparison of Methods

  6. Reversible Hydrogen Exchange in Metal Hydrides • H2 absorbed under pressure • H atoms bond to metal • H2 released at elevated temperature

  7. Sodium Alanate • 3NaAlH4 -> Na3AlH6 + 2Al +3H2 • Na3AlH6 -> 3NaH + Al + 3/2H2 • 5.6 % Hydrogen by Weight • $50 per kg • Slow Kinetics • Reversible only at ~600 K

  8. Ti-Doped Sodium Alanate • Reversible at ~450 K • Kinetics 2-4 times faster • Still unsatisfactory, but • Working model for possibility of catalytic improvement

  9. Sodium Alanate Structure • Body Centered Tetragonal • Space Group IA/4 • Lattice ~5x11 Ang.

  10. First Principle Calculations forSodium Alanate • Geometry • Electronic Structure • Energy of Formation

  11. First Principles Calculationsfor Ti-Doping • Structurally Stable • Ti Prefers to Substitute for Na • Ti Softens Al-H bonds • It is energetically favorable for Ti to drag extra H into the system

  12. First Principle Studies of Analogous Systems • MxH • Electronic Structure • Energy of Formation • Cohesive Energy • Metal-Hydrogen Bond Strength

  13. Local Projects • Comparing CASTEP to VASP • Reproducing Calculations in Literature • Sodium Alanate Structure (In Progress) • Energy of Formation • Titanium Valence (Population Analysis)?

  14. Conclusion • Ti – Doped Sodium Alanate Experiments show that Catalytic methods can be used to improve operation of Metal Hydrides • First Principle Calculations may lead to understanding of mechanism that will allow improved Catalytic Methods

More Related