Catalytic converter. Molecular graphic showing how a catalytic converter converts pollutants into harmless gases. The yellow framework is a lattice of copper atoms - the catalyst. Atoms of the poll- utant gases carbon monoxide (CO) and nitric oxide (NO) are shown adsorbed onto the copper surface (oxygen = red; carbon = green; nitrogen = blue). The reaction produces the harmless gases nitrogen (N2, upper right) and carbon dioxide (CO2, upper left). The blue and white zones show molecular orbitals involved in breaking apart a nitric oxide molecule over a cluster of 10 copper atoms (brown).