The History of Improving Automobile Emissions

In many urban areas, automobile transportation accounts for the majority of smog-forming emissions, and air pollution control legislation continues to spur the research and development of lower-emission automobiles. We describe here a laboratory project, suitable for the general chemistry or physical chemistry laboratory, which uses Fourier transform infrared (FTIR) spectroscopy for the analysis of automobile exhaust. Using this method, products of both complete and incomplete combustion of gasoline are identified in exhaust under various vehicle-operating conditions. By quantifying the level of carbon monoxide in exhaust from automobiles manufactured over a sixty-model-year range, students are able to understand the factors that reduce the emission of incomplete combustion products.