Catalysts

• catalyst - substance that increases the rate of reaction without being used up during the process
• a catalyst works by increasing the rate of chemical reaction without being used up in the process :
• Types of catalysts

  • homogeneous catalysts
  • heterogeneous catalysts
• Homogeneous catalysts

  when a catalyst for a reaction is in the same phase as reactants
• Heterogeneous catalysts

  when a catalyst for a reaction is in a different phase as the reactants
• Phases do not just include states of solid, liquid, gas. If all the chemical are immiscible liquids (they do not mix) the catalyst could still be heterogeneous, as it could be in a different liquid layer from reactants
• Economic importance of catalysts

  • help lower energy demands of processes + so reducing costs + help environment

  -> less fossil fuel needs to be burned to generate the required energy + therefore lower carbon dioxide emissions

  • catalytic converters play an important role in improving air quality by reducing toxic emissions from vehicles + preventing photochemical smog