Characteristics of Catalysts
1. The catalyst remains unchanged in mass and chemical composition.
2. In case of reversible reactions, the catalyst does not influence the composition of reaction mixture at equilibrium. It only helps to attain the equilibrium quickly.
Promoters and Poisons
Promoters are chemical substances that enhance the activity of a catalyst while poisons decreases the activity of a catalyst
Adsorption Theory of Heterogeneous Catalysis
The mechanism involves five steps: Diffusion of reactants to the surface of the catalyst
Adsorption of reactant molecules on the surface of the catalyst.
Occurrence of chemical reaction on the catalyst’ s surface through formation of an intermediate.
Desorption of reaction products from the catalyst surface.
Diffusion of reaction products away from the catalyst’ s surface