Which of the following decreases the rate of reactions?

Catalytic poison Heterogeneous catalyst Homogeneous catalyst Catalytic promoters

Catalytic poison

A catalytic poison is a substance which destroys the activity of the catalyst even if it is present in trace amounts. For instance, any arsenic contaminant found in the gases interacting during the production of sulfuric acid by the contact process will render the vanadium pentoxide catalyst inactive.