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Catalysts for Gasoline Engines (Light-Duty Vehicles or "LDVs")
Introduced in 1975, the catalytic converter has been the pervasive means of meeting emissions regulations for gasoline-powered vehicles around the world. Since 2005, 100% of new cars sold in the U.S. and over 90% of all new cars sold worldwide have been equipped with a catalytic converter as the principal means of meeting emissions standards. A catalyst is a substance that facilitates a chemical reaction without taking part in the reaction itself. Environmental catalytic converters convert harmful compounds into innocuous compounds. For example, three-way automotive catalytic converters convert hydrocarbon, nitrogen oxide and carbon monoxide into nitrogen, carbon dioxide and water. Catalytic converters are made up of several different components contained in a metal housing that is incorporated into an automobile's exhaust system. These systems may contain multiple catalytic converters, each of which may contain several ceramic substrates. Each ceramic substrate is made from widely available materials formed into a honeycomb array of porous channels designed to maximize the surface area exposed to passing exhaust gasses. Each substrate is coated with an active catalyst coating that contains tiny particles of precious metals, which serve chemically to clean the exhaust. Once exhaust heats the coated substrates above 300 degrees Celsius, hydrocarbon, nitrogen oxide and carbon monoxide molecules bind temporarily to the catalyst surface and are converted into innocuous compounds. The regulations controlling auto emissions in countries throughout the world have become increasingly restrictive, and will continue to tighten in the future. In the United States, emissions standards are managed by the Environmental Protection Agency (EPA). The state of California has special dispensation to promulgate more stringent vehicle emissions standards, and other states may choose to follow either the national or California standards. According to a 2005 EPA study, the largest emissions of nitrogen oxide came from on-road motor vehicles, with the second largest contributor being non-road equipment (mainly gasoline and diesel engines). The study also lists on-road vehicles as the second largest source of volatile organic compounds at 26%, with non-road equipment at 19%. According to the same study, on-road vehicles were responsible for 60% of carbon monoxide emissions and motor vehicle use is increasing. Nationwide, three-quarters of carbon monoxide emissions come from on-road motor vehicles (cars and trucks) and non-road engines (such as boats and construction equipment). Control measures have reduced pollutant emissions per vehicle over the past 20 years, but the number of cars and trucks on the road and the miles they are driven have doubled in the past 20 years. Vehicles are now driven two trillion miles each year in the United States. With more and more cars traveling more and more miles, growth in vehicle travel may eventually offset progress in vehicle emissions controls. Emission control catalysts eliminate dangerous engine pollutants from a range of fuels, including gasoline, diesel, natural gas and alternative fuels. Our Solution
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