Explanation:
Homogeneous catalysis refers to catalytic reactions where the catalyst is in the same phase as the reactants.
Heterogeneous catalysis is the type of catalysis where the phase of the catalyst differs from the phase of the reactants or products.
Platinum is used to catalyze the hydrogenation of ethylene:
H2(g)+CH2CH2(g)− ⟶ Pt(s) CH3CH3(g)
In this reaction, the platinum is in the solid state. While the other species (reactants and products) are in their gaseous state.
This reaction is Heterogenous catalysis.
Chlorofluorocarbons (CFCs) catalyze the conversion of ozone (O3O3) to oxygen gas (O2O2):
2O3(g)− ⟶ CFC(g) 3O2(g)
The catalyst is in the same gaseous state as the reactant and product.
This reaction is Homogenous catalysis.
Magnesium catalyzes the disproportionation of hydrogen peroxide to produce water and oxygen:
2H2O2(aq)− ⟶ Mg(s) 2H2O(l) + O2(g)
In this reaction, the Magnesium is in the solid state. While the other species (reactants and products) are in their gaseous state.
This reaction is Heterogenous catalysis.
