Fuel Identification and Design at CFCI

• The first new fuels that we will study in this research belong to the class of alkynols and alkynediols

• It has been recognized for some time that oxygenated compounds have some advantages over simple hydrocarbons as fuel-cell fuels. This include:
  • lower volatility
  • lower oxidation potentials
  • cleaner oxidation
• However, the clear disadvantage is that they also have a lower gravimetric specific energy.
• At CFCI we have sought to incorporate all of the benefits of oxygenates into our new fuels, while mitigating the problem of lower specific energy.
• Electrochemical oxidation of most oxygenated fuels will begins by removal of a nonbonding electron from one of the oxygen lone-pair orbitals, since electrons of this kind are generally the least-tightly bound in the molecule. When the oxygen-containing functional group is a primary or secondary alcohol, this initial event is followed quickly by conversion of the alcohol into a carbonyl compound.
• We have designed our fuels in such a fashion that this initial oxidation step creates a conjugated molecule in which the C=C triple bond becomes activated to water addition by virtue of the newly created carbonyl group(s).
  • water addition begins the process of oxidative degradation of the carbon skeleton—a crucial step if complete oxidation of the fuel to CO₂ and H₂O is to be accomplished.
• In the diagram below, we illustrate a plausible mechanism that is taken as far as the first C–C bond scission. Subsequent steps will depend on the nature of the substituents, but will follow similar general lines.

• Our new fuels are designed to recover some of the specific energy advantages of compounds with lower oxygen content while providing mechanistic pathways that can facilitate complete oxidation.
• The syntheses of the compounds that we propose to study are most readily accomplished by the reaction of metal acetylides or carbides with low-molecular-weight aldehydes, which can be obtained from renewable sources.