How titanium dioxide crystals on noxer block catalyse oxidation reaction that remove NOx from the atmosphere?

Answer 1

Titanium dioxide absorbs the radiation which is given off from the sun. This excites the electrons in titanium dioxide to a higher energy level. The high energy electron from titanium dioxide reacts with oxygen to produce a superdioxide ion on the surface of the titanium dioxide crystals; O2 +e- O2- Water also reacts with the oxide to produce a hydrogen, hydroxyl radical and an electron which is given back to the titanium dioxide; H2O + O2 H+ + OH + e- "The overall reaction is therefore; H2O + O2 H+ + O2- + OH" The hydroxyl radical formed can then oxidise nitrogen dioxide to nitrate ions because it is a very powerful oxidising agent; NO2 + OH H+ + NO3- More of the nitrogen gases can be rendered as the superoxide produced on the surface of titanium oxide can be used to convert nitrogen monoxide into nitrate ions; NO + O2- NO3- Titanium dioxide absorbs the radiation which is given off from the sun. This excites the electrons in titanium dioxide to a higher energy level. The high energy electron from titanium dioxide reacts with oxygen to produce a superdioxide ion on the surface of the titanium dioxide crystals; O2 +e- O2- Water also reacts with the oxide to produce a hydrogen, hydroxyl radical and an electron which is given back to the titanium dioxide; H2O + O2 H+ + OH + e- "The overall reaction is therefore; H2O + O2 H+ + O2- + OH" The hydroxyl radical formed can then oxidise nitrogen dioxide to nitrate ions because it is a very powerful oxidising agent; NO2 + OH H+ + NO3- More of the nitrogen gases can be rendered as the superoxide produced on the surface of titanium oxide can be used to convert nitrogen monoxide into nitrate ions; NO + O2- NO3-