Question

The substance that __________ the activity of catalysts is poisoner.
1. increases
2. decreases
3. maintains
4. none

Answer 1

Promoters/Activators : Substance which themselves are not catalyst but its presence can increase the catalytic activity of catalyst. A promoters increase the number of active sites on the surface.

Catalytic Poisons/ Anti catalysts/ Catalyst Inhibitor are those substances which themselves are not catalyst but whose presence decreases the activity of the catalyst. Poisoning is due to preferential adsorption of poison on the surface of the catalyst.