Tributylamine (TBA) was found to be effective in promoting the cracking of heptane. The conversion of heptane and the yield of gas product are both distinctly accelerated. The selectivity of propylene is remarkably promoted compared with that by cracking pure heptane at 550 degrees C, while at the higher temperature of 600 degrees C, the selectivity of all gas products changes very little. The cause to this effect could be that the butyl radical and its derivatives derived from TBA capture hydrogen from the heptane. (C) 2007 Elsevier Ltd. All rights reserved.