Chemical Sciences Colloid and Surface Chemistry Lab  Experiments

Study of the Catalytic Effects of Finely Divided Particles

Most of the products that we use today have involved catalysts at some stages of their production. Metals and metal oxides are highly desirable as catalysts in the chemical industry, fuel cells, waste reduction, bioprocessing, and so on. Finely divided particles have been used as catalysts for years due to their large surface areas. We are familiar with the catalytic properties of finely divided particles of transition metals like platinum, palladium, etc. Though colloidal gold particles have been used for centuries in medicines, colouring ceramics and glasses, etc., gold was not used as catalyst till recently due to its inert nature. In the following we study the use of different sized gold particles as catalysts for the reduction of an organic dye, eosin. The progress of the reaction can be followed spectrophotometrically.