Development of a Low Precious-metal Automotive Perovskite Catalytic System for LEV-II 2003-01-0814
For global environmental protection and resource conservation, Honda has developed a low precious-metal perovskite catalyst system in response to LEV-II, which achieves both low emissions and a reduction in the amount of precious metal used. The amount of precious metals used in the catalyst, per vehicle, is expected to be 50% less than in conventional systems. This system is comprised of an air-fuel ratio control system based on Honda's unique high-accuracy air-fuel control system, combined with a perovskite catalyst jointly developed with the US Company CSI. This system's performance is expected to reach the levels required by LEV-II regulations.
Perovskite is a mix-metal oxide material that is widely used in general applications other than catalysts. However, it has not been widely used in automobile catalysts, because, in comparison with precious-metal catalysts, both the heat resistance and conversion efficiency during the warm-up process is reduced. In the new system, CSI's MPC (mixed phase catalyst) technology and Honda's quick warm-up system are combined, improving both heat resistance and conversion efficiency during warm-up, and thereby making it possible to achieve performance that is comparable to that of a precious-metal catalyst. With the use of this system, a 2.4L inline 4-cyliner engine vehicle having 2g of precious metal is expected to achieve LEV-II regulation levels.