Catalytic converters and global warming Flashcards
What are the uses of a catalytic converter?
cars a fiitted with catalytic converters in their exhaust to reduce the output of CO, NOx and unburnt hydrocarbons
What is the structure of the catalytic converter?
honeycomb made of a cermaic material coated with platinum and rhodium metals
Why is this structure used
the platinum and rodium are catalysts the honeycomb shape provides an enormous surface area
What is the reaction to reduce CO and NO
2CO (g) + 2NO (g) -> N2 (g) + 2CO
What is the reaction to reduce NOx and unburnt hydocarbons?
hydocarbons + nitrogen oxide -> nitrogen + carbon dioxide + water
Where do these reactions take place?
on the surface of the catalyst, on the layer of metal
How do greenhouse gases cause the greenhouse effect?
they trap infrared radiation so the earth’s atmosphere heats up
this is important in sustaining life
other gases such as methane and water vapour but they have not been as much change
What is the problem with water vapour?
water vapour concentrations tend to stay constant due to the equilibrium between gaseous water and liquid
although a rise in temperature will cause more water to form, and therefore more globabal warming
What does the carbon neutral mean?
activites that have no net release of carbon
Why is only a thin layer of metals used?
to reduce the amount of metals needed
increase SA of catalyst
How does the greenhouse effect occur
bonds vibrate
