1. Industrial Uses Of Catalysts  Berzelius (1836) realised that there are substances Which increase the rate of a reaction Without themselves being consumed. He believed that the function of such a substance was to loosen The bonds which hold the atoms in the reacting molecules together. Thus he coined the term Catalysis. Uses of catalysis it is based on this types, 1.Positive catalysis 2.Negative catalysis 3.Homogeneous catalysis 4.Hetrogeneous catalysis 5.Acid- Base catalysis 6.Enzyme catalysis 7.Autocatalysis

2. Homogeneous Catalysis  the catalyst is in the same phase as the reactants and is evenly distributed throughout.  This type of catalysis can occur in gas phase or the liquid phase.  Homogeneous Catalysis in gas phase:  Oxidation of sulphur dioxide (SO2) to sulphur trioxide ( SO3) with nitric oxide (NO) as catalyst. 2SO 2 + O 2 + [NO]  2SO 3 +[NO] gas gas gas gas  Decomposition of acetaldehyde (CH3CHO) with iodine (I2) as catalyst. CH 3 CHO + (I 2 )  CH 4 + CO vapour vapour gas gas  Homogeneous catalysis in solution phase:  Hydrolysis of can sugar in aqueous solution in the presenceof mineral acid as catalyst, C 12 H 22 O 11 + H 2 O  C 6 H 12 O 6 + C 6 H 12 O 6 + [H 2 SO 4 ] cane sugar glucose fructose

3. Heterogeneous Catalysis  The catalytic process in which the reactants and the catalyst are in different phases is known as heterogeneous catalysis. pt (s) 2SO 2(g) + O2(g)  2SO 3(g) BrV 2 O 5 Fe (s) N 2(g) + 3H 2(g)  2NH 3(g) Positive catalysis :  When the rate of the reaction is accelerated by the foreign substance, it is said to be a positive catalyst. MnO 2(S) 2KClO 3(S)  2KCl (S) (+3O 2(g)

4. Negative catalysis:  When a catalyst reduces the rate of reaction, it is called a negative catalyst or inhibitor.  Decomposition of Hydrogen peroxide. 2H 2 O 2  2H 2 O +O 2 Applications of Catalysis  Industrial applications Almost all chemical industries have one or more steps employing catalysts Petroleum, energy sector, fertiliser, pharmaceutical, fine chemicals…. Modern cars have a catalytic converter to help reduse the production of toxic gases. catalytic converters use a platinum and rhodium catalyst. Increases the speed that (harmful) carbon monoxide and unburnt fuel reacts with oxygen from the air-help protect the environment. the catalysts are designed to work best at the high temperature found in the engine.

5. In chemical industry…, Hydrogen Industry (coal, hydrogenations, etc.) Natural gas processing. Petroleum refining. Petrochemicals (monomers, bulk chemicals ). Fine chemicals (pharma, agrochem, fragrance, textile, coating, surfactants, laundry etc). Environmental catalysis ( autoexhaust).