Question

Which kind of catalysis can be explained on the basis of adsorption theory?

• A. Homogeneous catalysis
• B. Heterogeneous catalysis
• C. Negative catalysis
• D. Auto catalysis

Answer 1

The correct option is B Heterogeneous catalysis

• The reactants in gaseous state or in solutions, are adsorbed on the surface of the solid catalyst. The increase in concentration of the reactants on the surface increases the rate of reaction. Adsorption being an exothermic process, the heat of adsorption is utilised in enhancing the rate of the reaction.
  

Heterogeneous catalysis 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, and thereby, making the surface available again for more reaction to occur.
  
• Diffusion of reaction products away from the catalyst’s surface.