In 2009, chemists working for the U.S. Navy studied Fischer-Tropsch for making fuels with hydrogen from electrolyzed seawater. With the usually optimal cobalt catalyst, this study produced mostly methane gas. Use of an iron catalyst, however, resulted in only 30% methane in the product; the rest consisted of short-chain hydrocarbons. Further refining of the hydrocarbons produced could lead to the creation of kerosene-based jet fuel.