Question

Explain the mechanism of homogeneous catalysis?

Answer 1

In homogeneous catalysis, the catalyst and the reactants are present in the same physical state, usually in the gaseous or liquid phase. The catalyst first combines with one or more reactants to form an intermediate compound, which then reacts further to provide the final product. In the process, the catalyst is regenerated and remains unchanged at the end of the reaction.

For example, in the oxidation of sulfur dioxide (SO₂) to sulfur trioxide (SO₃) in the lead chamber process, nitric oxide (NO) acts as a homogeneous catalyst.

The reaction proceeds as follows:

\[\ce{2NO + O2 -> 2NO2}\]

\[\ce{2SO2 + 2NO2 -> 2SO3 + 2NO}\]

Here, NO is used and regenerated during the reaction, and all substances involved are in the gaseous phase. Hence, it is an example of homogeneous catalysis.