A catalyst solution comprising one or more compounds of a metal catalyst and an organic solvent selected from the group consisting of a glycol derivative, an alkyl pyrrolidone, and an alkoxy ethyl ether, wherein no additional chloride-containing compounds are added to the solution. The metal can be selected from the group consisting of platinum, rhenium and rhodium. The compounds can be selected from the group consisting of H.sub.2 PtCl.sub.6.6H.sub.2 O, Re.sub.2 (CO).sub.10, Re.sub.2 O.sub.7, LiReO.sub.4 and RhCl.sub.3.4H.sub.2 O. The catalytic solutions are useful in conversion of pollutants from automotive engines and the like. In a particularly preferred embodiment, the solution contains three metals: platinum, rhenium, and rhodium.