Abstract: One or more embodiments relate to stable catalysts prepared through the encapsulation of platinum particles inside an alumina framework. These catalysts do not sinter at 800° C. in the presence of oxygen and steam, conditions in which conventional catalysts sinter to large extents, while showing similar reaction rates. Extending this approach to Pd/Pt bimetallic catalysts leads to maintained small particle size at temperatures as high as 1,100° C. in air and steam. This strategy can be broadly applied to other metal and metal oxides for applications where sintering is a major cause of materials deactivation.