A method of making a catalyst composition, comprising impregnating a large pore zeolite support with a platinum precursor and at least one organic ammonium halide precursor. In an embodiment, the ammonium halide precursor is represented by the formula N(R).sub.4X, where X is a halide and R is a substituted or unsubstituted carbon chain molecule having 1 20 carbon atoms wherein each R may be the same or different. In an embodiment, the ammonium halide precursor comprises at least one acid halide and at least one ammonium hydroxide represented by the formula N(R').sub.4OH, where R' is hydrogen or a substituted or unsubstituted carbon chain molecule having 1 20 carbon atoms wherein each R' may be the same or different. A process for aromatizing a hydrocarbon using said catalyst composition.