What are homogenous catalyst? Give few examples.

Question

When a catalyst mixes homogeneously with the reactants and forms a single phase, the catalyst is said to be homogeneous and this type of catalysis is called homogeneous catalysis. Some more examples of homogeneous catalysis are:
    
SO₂ is oxidized to SO₂ in the presence of nitric oxide (NO) as catalyst.

 
    
Oxidization of CO by O₂ in the presence of NO as catalyst.

 
    
Preparation of diethyl ether from ethyl alcohol using conc. H₂SO₄ as catalyst

 
    
Hydrolysis of esters using H₂SO4 as catalyst

 
    
Hydrolysis of sucrose in the presence of dilute sulphuric acid.

 

Mechanism of homogeneous catalysis 

As pointed out earlier, the catalyst combines with one of the reactant to form some intermediate compound. The intermediate compounds being unstable decompose or combine with each other reacting species to regenerate the catalyst along with the formation of final products. Let us understand the catalytic action of NO in the oxidation of SO₂.
 
In this reaction, NO (the catalyst) combines with oxygen to form NO₂ (intermediate). The intermediate is consumed in the next step and the catalyst is regenerated.