A substance, not itself a catalyst, that increases a catalyst's activity when added in small amount

A substance that destroys catalyst activity

A substance that decreases the reaction rate

A reactant that is consumed in the reaction

How can a promoter increase the activity of a catalyst?

By increasing the active sites (surface or crystal defects) or improving reactant adsorption

By lowering the temperature to zero

By changing the products formed

2069 Bhadra · 1.5 marks

Promoters in catalysis

Short answer

Promoters are substances that increase a catalysts activity when added in small amounts, such as by increasing active surface or creating defects. Examples include Mo for iron in Habers process and Cr₂O₃ for Fe₂O₃ in the water-gas shift reaction.

Explain the term: Promoters.

Promoters (activators) are substances that, though not themselves catalysts, increase the activity of a catalyst when added in a small quantity. They may increase the active surface or change the crystal structure (creating more defects/active sites), or they may improve the adsorption of the reactants.

In Haber's process, Mo (or Al₂O₃ + K₂O) is a promoter for the iron catalyst.
In the water-gas shift reaction, Cr₂O₃ promotes Fe₂O₃.
Cu promotes Ni in some hydrogenation reactions.

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