In the present study the catalytic activities of several TiO2-Supported metal and metal oxide catalysts have been tested simultaneously for the selective catalytic reduction of nitrogen oxides with ammonia (NH3-SCR) using high-throughput-screening equipment. Two different series of various catalyst samples were evaluated for different feed gas compositions, both with and without water, and before and after SO2 exposure. The first series of samples consisted of catalysts containing a single metal or metal oxide (Mg, V, Cr, Mn, Fe, Co, Ni, Cu, Mo, Rh, Ag, W, Ir, or Pt), including a commercial SCR catalyst sample for comparison. Of the metals investigated in the first series, Cr, Mn, Fe, and Rh were found to have the most interesting catalytic properties, regarding activity and selectivity at high or low temperatures. A second series of samples were prepared containing combinations of the selected metals, and the results from the catalytic tests show a general trend of increased SCR activity at lower temperatures when Rh is added to the multiple-metal samples. The results further indicate that it is possible to widen the active temperature window by combining different metals in the catalyst formulation.