ChemistryCode 9701
Homogeneous and heterogeneous catalysts
What this topic asks you to be able to do
- explain that a catalyst may be either homogeneous or heterogeneous
- describe how a heterogeneous catalyst works, covering adsorption of the reactants, weakening of bonds and desorption of the products, for example: (a) iron, used in the Haber process (b) palladium, platinum and rhodium, which catalyse the removal of nitrogen oxides from car engine exhaust gases
- describe how a homogeneous catalyst works by taking part in one step and being re-formed in a later one, with examples: (a) oxides of nitrogen in the atmosphere, catalysing the oxidation of sulfur dioxide in the air (b) Fe2+ or Fe3+ in the I–/S2O82– reaction