What are the important features of solid catalysts?

The two most important features of solid catalysts, which determine the effectiveness of the catalyst, are activity and selectivity. 

Catalytic Activity

A catalyst’s activity refers to its capacity to speed up a specific reaction. The strength of chemisorption is the primary factor that determines a catalyst’s activity. 

Catalytic surfaces and their reactants must produce bonds that are neither too strong nor too weak. While the reactants must be strongly adsorbed on the catalyst to activate it, if they are too strongly absorbed, they become immobilized, leaving no space available on the surface of the catalyst for new molecules to adsorb. 

Catalytic Selectivity

A catalyst’s selectivity refers to its ability to guide a reaction to yield a specific product selectively when the same reaction conditions could potentially create several other products using a different catalyst. For example, using different catalysts yields different products in the reaction of H2 and CO. 

Catalysts are extremely specialized molecules that are highly selective in nature. The selectivity of different catalysts varies for the same reactants. A specific catalyst can catalyze only one specific type of reaction while inhibiting another.