button: text-only site map
Heterogeneous and Homogeneous Catalysis

 

Homogeneous catalysis

The catalyst and reactants are in the same phase, usually liquid.

Examples are

 

 

Advantages


There is good contact with reactants so a much greater effective concentration of catalyst than with heterogeneous catalysts. This means that to achieve the same rate milder conditions can be used and so it is possible to achieve greater selectivity.

At the research and development stage it is often quicker and simpler to work with homogeneous catalysts, and then find ways of making the system heterogeneous for industrial application.


Disadvantages

The catalyst needs to be separated after reaction. This separation can involve distillation.

In some cases this makes catalyst recovery difficult because the temperature needed for the distillation can destroy the catalyst

 

 

Heterogeneous catalysis

Catalyst and reactants are in different phases, either

reactants: gases
catalyst:
solid

reactants: organic liquids or aqueous solutions
catalyst: solid

It is easier to study gas reactions.

 

examples

ammonia
fuel cell
catalyic convertor
hydrogenation
Friedel Crafts

 

 

 

 

 

Some examples of heterogeneous catalysts are

 

 

 

 

 

Advantages

Disadvantages