Ah, you want a dehydrogenation, now that is a tricky one, usually you start with a feedstock that already has double or triple bonds. There are some specialized catalysts for this purpose, as I understand it some rare-earth oxides, at high temps, will steal two hydrogens from a carbon chain, producing a double bond and water.
*[EDIT]*
Oh, the gang's all here, aren't they? We should just use the shout out function.