Acceleration and retardation of the cracking of hydrocarbons in various media

1. It was found that the pyrogenetic transformations of heptane in the molten metals aluminum, tin, and sodium proceed selectively in a way dependent on the nature of the metal. 2. Aluminum and tin accelerate the cracking of heptane. Sodium and potassium hydroxide exert a powerful retarding action on the cracking of heptane. 3. The mechanism of the action of inhibiting additives appears to amount to chain termination due to the reaction of alkali metals with free radicals or to the saturation of hydrogen liberated by reaction with hydrocarbons. 4. Alkali-metal hydroxides may be reduced by hydrocarbons to metals, which then react by the mechanism indicated.