Computational Study of Low-Temperature Catalytic C-C Bond Activation of Alkanes for Portable Power

Abstract

The development of a room temperature (<50C) fuel cell that could use a generally available fuel such as JP8 would be most valuable. However there are no known catalysts that can selectively activate the CC bonds of such fuels at such temperature. The goal of this project was to investigate the whether it is plausible to develop such a catalysts. To do this we used validated first-principles (quantum mechanics) based simulations to investigate the barriers for alkyl carbon-carbon cleavage for two prototypical systems: A metal alloy catalyst & An organometallic cluster catalyst. That might serve as an anode for electrochemical power generation. For the metal alloy catalyst we used a Top&#8208;down approach where we determined the bond energies to the alloy catalyst to various fuel fragments necessary to achieve room temperature decomposition of butane and oxidation to CO2. For organometallic cluster catalyst we used a bottom&#8208;up strategy, determining specific metals, ligand compositions, solvents and operating conditions to evaluate which conditions could lead to reasonable rates at room temperature. For the bottom up approach we the density functional theory (DFT) form of quantum mechanics to investigated homogeneous catalysts. We decided that Rh is the best metal for a low temperature oxidation of C-H and C-C bonds. We then considered a number of possible mechanisms and reaction pathways for butane oxidation. The lowest barriers we determined for these mechanisms are 30 kcal/mol, which is probably too high for reasonable rates at room temperature (probably requiring ~200C). We then began a study of Rh/O2 complexes, such as spin singlet RhCl3(O2)2- and the spin doublet RhIII superoxide complex RhCl3(H2O)(O2)1-,which we consider would be accessible under reaction conditions. We conclude that these might serve as 3- or 4-electron oxidants. Further research is needed to draw a firm conclusion about prospect of these and other possible metal complexes to provide s

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Document Details

Document Type
Technical Report
Publication Date
Jun 05, 2013
Accession Number
ADA587289

Entities

People

  • William Andrew Goddard III

Organizations

  • California Institute of Technology

Tags

DTIC Thesaurus Topics

  • Air Force Research Laboratories
  • Alkanes
  • Chemical Synthesis
  • Chemistry
  • Decomposition
  • Density Functional Theory
  • Energy
  • Fuel Cells
  • Hydrocarbon Fuels
  • Low Temperature
  • Materials Science
  • Mechanics
  • Molecular Dynamics
  • Organic Chemistry
  • Oxidation
  • Quantum Mechanics
  • Simulations

Readers

  • Electrochemical Engineering/ Fuel Cell Technologies
  • Materials Science and Engineering.
  • Organic Chemistry

Technology Areas

  • Biotechnology
  • Microelectronics
  • Quantum Computing