4 April 2012
As explained by Antonio Torrisi, MSc Science Communication
In nature, spontaneous chemical reactions can be fast like combustion, or slow like rust formation. Catalysis is the field of chemistry that pushes slow chemical reactions to go faster. A catalyst loosens the chemical bonds in a molecule and can be seen as a pair of scissors cutting the ties between atoms. The catalyst causes the molecule to break down into smaller parts which can quickly form new bonds with another molecule and ultimately generate new molecules. Catalysis can be homogeneous, where catalyst and reactive species are in the same physical state, or heterogeneous, where the catalyst is in a different physical state compared to the reagents (those substances taking part in the chemical reaction). Biomolecules called enzymes are examples of homogeneous catalysts that control the chemical reactions in living beings. Metals like platinum act like heterogeneous catalysts in catalytic converters of cars to transform toxic gases, products of the engine’s combustion, into gases such as CO2 and nitrogen.