Results of studies during the first nine months of a project sponsored by the Department of Energy (DOE), Morgantown Energy Technology Center (METC), are reported. The primary objective of these studies is to develop a catalyst which will convert sulfur in coal tars to a form (such as H/sub 2/S) which can be removed by a hot gas desulfurization process being developed by DOE/METC and will also convert the tars to compounds that cannot crack and deposit coke on the electrodes of a molten carbonate fuel cell (MCFC). The system for tar destruction will operate in conjunction with the desulfurization process. Results of a literature search and initial catalyst screening tests are presented. Nine different catalysts were selected and tested in the completed screening tests. The effects of temperature, pressure, and residence time on tar conversion were also evaluated. A low-sodium type Y-zeolite and catalysts made by impregnating CoMo, NiMo, and Pt on this zeolite were superior to other catalysts tested. In four hour screening tests, average tar conversions with these catalysts for two different tar samples ranged from 60 to 80% based on total tar. Sulfur conversion ranged from 80 to 90%. All catalysts lost activity with time. Tar conversion with the Y-zeolite catalysts decreased from about 90% in the first hour to about 50% after 4 hours. The effects of temperature, pressure, and residence (contact) time on catalyst activity are discussed. 28 refs., 7 figs., 13 tabs.