Nano-size metals and alloys are well known to display extremely high catalytic activity for many chemical reactions due to their high percentage of surface atoms. The stability of these nano catalysts is just as, or even more important than activity when used under extreme conditions adopted in industry. Most nano particles undergo surface reconstruction at high temperatures, and are very susceptible to surface poisons. We report a new research, mentioned in this thesis, which clearly demonstrates that encapsulation of a metal nanoparticle with carbon by a simple hydrothermal treatment of glucose is able to offer a protective jacket to the enclosed metal. As a result, 5 nm platinum particle stabilised inside the carbonaceous cage which protects the metal against sintering even at 1000 °C, and after extreme treatments, the material is still active with sufficient surface area for catalytic hydrogenation reactions.