What do you mean by activity and selectivity of catalysts?
Answers
(a) Activity of a catalyst:
The activity of a catalyst is its ability to increase the rate of a particular reaction. Chemisorption is the main factor in deciding the activity of a catalyst. The adsorption of reactants on the catalyst surface should be neither too strong nor too weak. It should just be strong enough to make the catalyst active.
(b) Selectivity of the catalyst:
The ability of the catalyst to direct a reaction to yield a particular product is referred to as the selectivity of the catalyst. For example, by using different catalysts, we can get different products for the reaction between H2 and CO.
The activity of a catalyst can be termed as the ability of increasing of a particular reaction rate.
Chemisorption acts as the leading factor while deciding the activity of a catalyst.
On the other hand, the activity of a catalyst to direct the reaction for yielding the particular product refers to the selectivity of a catalyst.