Effect of catalysts

The rate of a reaction can be increased by adding a suitable catalyst.

curriculum-key-fact
A catalyst is a substance which changes the rate of reaction but is unchanged at the end of the reaction.

Only a very small amount of catalyst is needed to increase the rate of reaction between large amounts of reactants.

A catalyst is specific to a particular reaction:

  • different catalysts catalyse different reactions
  • not all reactions have suitable catalysts
Graph showing how effective Manganese (IV) oxide, Copper (II) oxide, and Zinc oxide are as catalysts for the decomposition of hydrogen peroxide.Graph showing effectiveness of different metal oxides as catalysts for the decomposition of hydrogen peroxide

This table summarises some common catalysts used in industry and the reactions they catalyse:

CatalystReaction catalysed
IronMaking ammonia from nitrogen and hydrogen
PlatinumMaking nitric acid from ammonia
Vanadium(V) oxideMaking sulfuric acid