- (B) The three reactions that occur in catalytic converters are:
(a) Reduction of nitrogen oxides to nitrogen and oxygen:
NOx → O 2 + N 2
(b) Oxidation of carbon monoxide to carbon dioxide:
CO + O 2 → CO 2
(c) Oxidation of unburned hydrocarbons to carbon dioxide and water:
CxH2x + O 2 → CO 2 + H 2 O
Although catalytic converters are effective at removing hydrocarbons and
other harmful emissions, they do not reduce the emission of carbon dioxide
produced when fossil fuels are burned. Catalytic converters are a significant
and growing cause of global warming because of their release of nitrous
oxide (N 2 O), a greenhouse gas over 300 times more potent than carbon
dioxide. Motor vehicles contribute approximately 50% of nitrous oxide
emissions, and nitrous oxide makes up 7% of greenhouse gases.
