Nitric oxide, polluted atmospheres oxygen

In polluted urban atmospheres, singlet molecular oxygen may play an essential part in the oxidation of nitric oxide to nitrogen dioxide.5,6 The... 

Another important application of heterogeneous catalysts is in automobile catalytic converters. Despite much work on engine design and fuel composition, automotive exhaust emissions contain air pollutants such as unburned hydrocarbons (CxHy), carbon monoxide, and nitric oxide. Carbon monoxide results from incomplete combustion of hydrocarbon fuels, and nitric oxide is produced when atmospheric nitrogen and oxygen combine at the high temperatures present in an... 

Nitric oxide itself is a toxic pollutant and the U.S. Environmental Protection Agency (the EPA) includes it among the primary toxic pollutants it attempts to regulate. If this nitric oxide is able to escape the exhaust system of the engine, it reacts quite rapidly with atmospheric oxygen to produce nitrogen dioxide, a reddish-brown, highly toxic gas. 

Scientists have discovered that air pollution from the burning of fossil fuels is the major cause of acid rain. Acidic deposition, or acid ram, as it is commonly known, occurs when emissions of sulfur dioxide (SO ) and oxides of nitrogen (NOx) react in the atmosphere with water, oxygen, and oxidants to form various acidic compounds. This mixture forms a mild solution of sulfuric acid and nitric acid. Sunlight increases the rate of most of these reactions. 

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