A catalyst, method for preparing the catalyst, and method for using the catalyst having improved conversion and/or selectivity in the dehydrogenation of hydrocarbons. The catalyst being prepared by modifying and impregnating a mazzite zeolite. Modification of the original mazzite zeolite may include steps for ion-exchanging, dealuminating, physically mixing with chromic oxide, shaping, and calcining. Once modified, the mazzite zeolite may be impregnated with at least one metal selected from the group consisting of chromium, molybdenum, tungsten and oxides of these metals.