Study of Catalytic Control of Exhaust Emissions for Otto Cycle Engines

摘要

The state-of-the-art study concerns the development of catalytic control systems for the emission of oxides of nitrogen from motor vehicles. Since the control of oxides of nitrogen often is coupled with the control of hydrocarbons and carbon monoxide, the application of catalyst systems for the control of these emissions is also included. A number of catalysts were examined for efficient oxidation of hydrocarbons and carbon monoxide present in auto exhaust under different driving conditions. For the removal of oxides of nitrogen, the available experimental data are incomplete and meager. A promising approach to catalytic control of oxides of nitrogen appears to be its reaction with carbon monoxide in a two-stage catalytic system, although such a system has not been tested to any extent under road-test conditions. To some degree, all catalytic systems are affected by the composition of the exhaust gases with which they come in contact. All estimated costs and operation of the system are based on operating with lead-free fuel, since no catalyst system for oxides-of-nitrogen control has as yet been demonstrated that is resistant to leaded fuels for sufficient operating mileage to be of practical significance (for example, 50,000 miles or more). (Author)