“catalytic converter”的概念、定义、翻译、参考文献-科学参考

catalytic converter

Physics

A device used in the exhaust systems of motor vehicles to reduce atmospheric pollution. The three main pollutants produced by petrol engines are: unburnt hydrocarbons, carbon monoxide produced by incomplete combustion of hydrocarbons, and nitrogen oxides produced by nitrogen in the air reacting with oxygen at high engine temperatures. Hydrocarbons and carbon monoxide can be controlled by a higher combustion temperature and a weaker mixture. However, the higher temperature and greater availability of oxygen arising from these measures encourage formation of nitrogen oxides. The use of three-way catalytic converters solves this problem by using platinum and palladium catalysts to oxidize the hydrocarbons and the CO and rhodium catalysts to reduce the nitrogen oxides back to nitrogen. These three-way catalysts require that the air–fuel ratio is strictly stoichiometric. Some catalytic converters promote oxidation reactions only, leaving the nitrogen oxides unchanged. Three-way converters can reduce hydrocarbons and CO emissions by some 85%, at the same time reducing nitrogen oxides by 62%.

Chemistry

A device used in the exhaust systems of motor vehicles to reduce atmospheric pollution. The three main pollutants produced by petrol engines are: unburnt hydrocarbons, carbon monoxide produced by incomplete combustion of hydrocarbons, and nitrogen oxides produced by nitrogen in the air reacting with oxygen at high engine temperatures. Hydrocarbons and carbon monoxide can be controlled by a higher combustion temperature and a weaker mixture. However, the higher temperature and greater availability of oxygen arising from these measures encourage formation of nitrogen oxides. The use of three-way catalytic converters solves this problem by using platinum and palladium catalysts to oxidize the hydrocarbons and the CO and rhodium catalysts to reduce the nitrogen oxides back to nitrogen. These three-way catalysts require that the air-fuel ratio is strictly stochiometric. Some catalytic converters promote oxidation reactions only, leaving the nitrogen oxides unchanged. Three-way converters can reduce hydrocarbons and CO emissions by some 85%, at the same time reducing nitrogen oxides by 62%.

Chemical Engineering

A device used in the exhaust of internal combustion engines of motor vehicles to reduce the amount of harmful gases released into the environment. It consists of a chamber containing catalytic substances through which the exhaust gases flow. The catalyst converts unburnt hydrocarbons, carbon monoxide, and nitrogen oxide gases. Carbon monoxide is formed from the incomplete combustion of hydrocarbon fuel gases, and the nitrogen oxides or NOx are formed from the high temperature reaction of nitrogen with oxygen in the air. The catalysts used to oxidize the unburnt hydrocarbons and the carbon monoxide, and convert the nitrogen oxides back to nitrogen, include platinum, palladium, and rhodium. Their performance is, however, adversely affected by some chemicals such as tetraethyl lead once widely used in some forms of petrol.

单词	catalytic converter
释义	catalytic converter Physics A device used in the exhaust systems of motor vehicles to reduce atmospheric pollution. The three main pollutants produced by petrol engines are: unburnt hydrocarbons, carbon monoxide produced by incomplete combustion of hydrocarbons, and nitrogen oxides produced by nitrogen in the air reacting with oxygen at high engine temperatures. Hydrocarbons and carbon monoxide can be controlled by a higher combustion temperature and a weaker mixture. However, the higher temperature and greater availability of oxygen arising from these measures encourage formation of nitrogen oxides. The use of three-way catalytic converters solves this problem by using platinum and palladium catalysts to oxidize the hydrocarbons and the CO and rhodium catalysts to reduce the nitrogen oxides back to nitrogen. These three-way catalysts require that the air–fuel ratio is strictly stoichiometric. Some catalytic converters promote oxidation reactions only, leaving the nitrogen oxides unchanged. Three-way converters can reduce hydrocarbons and CO emissions by some 85%, at the same time reducing nitrogen oxides by 62%. Chemistry A device used in the exhaust systems of motor vehicles to reduce atmospheric pollution. The three main pollutants produced by petrol engines are: unburnt hydrocarbons, carbon monoxide produced by incomplete combustion of hydrocarbons, and nitrogen oxides produced by nitrogen in the air reacting with oxygen at high engine temperatures. Hydrocarbons and carbon monoxide can be controlled by a higher combustion temperature and a weaker mixture. However, the higher temperature and greater availability of oxygen arising from these measures encourage formation of nitrogen oxides. The use of three-way catalytic converters solves this problem by using platinum and palladium catalysts to oxidize the hydrocarbons and the CO and rhodium catalysts to reduce the nitrogen oxides back to nitrogen. These three-way catalysts require that the air-fuel ratio is strictly stochiometric. Some catalytic converters promote oxidation reactions only, leaving the nitrogen oxides unchanged. Three-way converters can reduce hydrocarbons and CO emissions by some 85%, at the same time reducing nitrogen oxides by 62%. Chemical Engineering A device used in the exhaust of internal combustion engines of motor vehicles to reduce the amount of harmful gases released into the environment. It consists of a chamber containing catalytic substances through which the exhaust gases flow. The catalyst converts unburnt hydrocarbons, carbon monoxide, and nitrogen oxide gases. Carbon monoxide is formed from the incomplete combustion of hydrocarbon fuel gases, and the nitrogen oxides or NOx are formed from the high temperature reaction of nitrogen with oxygen in the air. The catalysts used to oxidize the unburnt hydrocarbons and the carbon monoxide, and convert the nitrogen oxides back to nitrogen, include platinum, palladium, and rhodium. Their performance is, however, adversely affected by some chemicals such as tetraethyl lead once widely used in some forms of petrol.
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