Homogeneous & Heterogeneous Catalysis
- Catalysts increase the rate of reaction by providing an alternative pathway which has a lower activation energy
- Catalysts can be either homogeneous or heterogeneous
- Homogeneous catalysts are those that are in the same phase as the reaction mixture
- For example, in the esterification of ethanoic acid (CH3COOH) with ethanol (CH3CH2OH) to form ethyl ethanoate (CH3COOCH2CH3) under acidic conditions
- The H+ is a homogeneous catalyst as like the reactants and product it is in the aqueous phase
- Heterogeneous catalysts are those that are in a different phase to the rest of the reaction mixture
- For example, in the Born-Haber process to form ammonia (NH3) from nitrogen (N2) and hydrogen (H2) an iron (Fe) catalyst is used
- The Fe catalyst is a heterogeneous catalyst as it is in the solid phase whereas the reactants and products are all in the gas phase