$A$ catalyst in a chemical reaction

$A$ catalyst is a substance which

For the following Assertion and Reason,the correct option is
Assertion : For hydrogenation reactions,the catalytic activity increases from Group $5$ to Group $11$ metals with maximum activity shown by Group $7-9$ elements.
Reason : The reactants are most strongly adsorbed on Group $7-9$ elements.

$ZSM-5$ is used in which of the following processes?

According to the adsorption theory of catalysis,the rate of reaction increases because:

In a chemical reaction,a catalyst . . . . .