Types Of Catalytic Reactions

• Homogeneous catalysis.
• Heterogeneous catalysis.

Homogeneous catalysis:

       In homogeneous catalysis the catalyst in the same phase as the reactants. Typically everything will be present as a gas or contained in a single liquid phase.

        ( i ) Homogeneous catalysis involves the influence of  H⁺ on the esterification of carboxylic acids, such as the formation of methyl acetate from acetic acid and methanol.

         ( ii ) Oxidation of  SO₂  to SO₃ with oxygen in the presence of nitric oxide as the catalyst in the lead chamber process.

Heterogeneous catalysis:
      The catalytic process in which the reactants and the catalyst are in different phases is known as heterogeneous catalysis. Typical examples involve a solid catalyst with the reactants as either liquids or gases.
       ( i ) The Haber process finely divided iron serves as a catalyst for the synthesis of ammonia from nitrogen and hydrogen. The reactants are in the gaseous phase while the catalyst is in solid phase.

                                                                    Fe

                                       N₂     +     3H₂     →     2NH₃

        ( ii ) Another example of heterogeneous catalyst is applied in the oxidation of sulfur dioxide on vanadium (V) oxide for the production of sulfuric acid.

                                                                   V₂O₅

                                       2SO₂     +     O2     →     2SO₃
Hydrogenation of ethene on a solid surface.

Explanation.

     

      Ethene  molecule is adsorbed by the surface of the platinum.

       

        Hydrogen molecule adsorbed and broken into atoms. 

        Hydrogen atom form a bond with one of the carbon atom of ethene.

        Another hydrogen atom form a bond with another carbon atom of ethene.

         Now the product molecule is free.