There are catalysts which can take simple alkenes like ethene and propene to higher oligomers (e.g. hexene, octene), but those are mostly used as polymer feedstocks, not as fuels.
There is a lot of work focused on using methanol as a fuel or a fuel precursor. Most people are interested in converting methanol to methane and then using methane as a fuel. Converting methane (natural gas) to methanol is much more difficult, but it is preferrable because methanol is much, much easier to transport than methane.
Another fuel synthesis method is the Fischer-Trops process, which takes carbon monoxide and H2 to higher alkanes. Essentially you make synthetic gasoline. If I recall correctly, these processes tend to favor the formation of alkanes which are a little above the size of alkanes which are optimal for gasoline, but you can always crack the higher alkanes therrmally to make smaller ones.