Petroleum and natural gas contain significant amounts of sulfur compounds that are removed as H2S. H2S was converted into hydrogen and sulfur using a two-step process. In the first stage, H2S was reacted with an anthraquinone molecule in a polar solvent to produce a hydroanthroquinone and a sulfur precipitate. In the second stage, the solution containing the hydroquinone was passed through a catalyst bed to regenerate the anthraquinone and produce hydrogen gas. The formation of a paramagnetic diradical anthraquinone species and a HS- anion was thought to be critical in the first step of the reaction sequence. A heterogeneous catalyst was developed for the selective conversion of the hydroanthraquinone back to the anthraquinone and hydrogen, without formation of anthrone or anthranol. This is an abstract of a paper presented at the 231st ACS National Meeting (Atlanta, GA 3/26-30/2006).