The present invention provides methods of preparing an improved platinum catalyst for use in fuel cells. The method includes preparing a platinum-loaded template of mesoporous alumina, and preparing a platinum catalyst using said alumina template. To prepare the template, a platinum solution and an aluminum alkoxide-butanol solution are combined to form a mixture and the mixture is then subjected to hydration and condensation reactions. To prepare the platinum catalyst, the template and carbon precursors are subjected to polymerization, and the resultant composite subjected to heat treatment. Due to the uniform platinum particle size and high specific surface area achieved, the method of the invention can produce a platinum catalyst with high catalytic activity and thermal stability and in turn improve the performance of the fuel cell in which the catalyst is used.