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Promoters are substances which increase the efficiency of catalysts.

Last updated date: 13th Jun 2024
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Hint: As the name suggests, “Promoters” means any substance that promotes or activates a particular process. They are just opposite the substances known as “catalytic poisons”.

Complete answer:
Catalysts are an integral part of a chemical equation. They are substances which can alter the rate of the chemical reaction process. By increase of temperature, there is an increase in the catalytic power of a catalyst but after a certain temperature its power begins to decrease. Thus, a catalyst has a particular temperature at which its catalytic activity is maximum. The temperature is termed as optimum temperature.
A positive catalyst decreases the activation energy $({{E}_{a}}).$
Catalysts can be divided into two main types – Heterogeneous and Homogeneous.
a. In a heterogeneous reaction, the catalyst is in a different phase from the reactants.
b. In a homogeneous reaction, the catalyst is in the same phase as the reactants.
For example, Iron is used in the Haber’s process as a cheap catalyst.

In chemistry, Promoters are substances that are added to any solid catalyst to improve its performance in a chemical reaction. They have little or no catalytic effect. They are added to a catalyst to increase activity or selectivity. Thus, the promoter helps in increasing the efficiency of the catalyst. The active components of the catalysts get interacted by some promoters that lead to the alteration of their chemical effect on the catalyzed substance.

For example,
Molybdenum is used as a promoter for manufacturing during Haber's process.
Tin added to Platinum reforming catalysts to improvise selectivity to coke formation.
Chlorine is added to isomerisation catalysis to increase activity.

The correct option is A. True.

Note: Don't confuse the idea of Promoters with Catalysts. Both are totally different. In Haber’s process, Molybdenum is added to finely divided Iron to increase its activity. The catalytic poisons are substances that destroy the activity of the catalyst by their own presence in the chemical reaction. For example, the presence of ${{H}_{2}}S$ or $CO$ in the synthesis of ammonia by Haber’s process.