Explain the shape selective catalysis by zeolites.

(N/A) The catalytic reaction that depends upon the pore structure of the catalyst and the size of the reactant and product molecules is called shape-selective catalysis.
Zeolites are good shape-selective catalysts because of their honeycomb-like structures. They are microporous aluminosilicates with a three-dimensional network of silicates in which some silicon atoms are replaced by aluminium atoms,giving an $Al-O-Si$ framework.
The reactions taking place in zeolites depend upon the size and shape of reactant and product molecules as well as upon the pores and cavities of the zeolites. They are found in nature as well as synthesized for catalytic selectivity.
Zeolites are widely used as catalysts in petrochemical industries for the cracking of hydrocarbons and isomerisation. An important zeolite catalyst used in the petroleum industry is $ZSM-5$. It converts alcohols directly into gasoline (petrol) by dehydrating them to give a mixture of hydrocarbons.