Precious-metal-free automotive catalyst in the elements science and technology project

Nishihata, Yasuo; Matsumura, Daiju   

Self-regeneration of the intelligent catalyst as an automotive catalyst was observed by XAFS. Palladium nano-particles in catalytic reaction were also observed to elucidate the difference in activity between the intelligent catalyst and the conventional one. Copper has been investigated as a candidate to replace precious metals since the first-principle theory predicts an active copper surface for NO dissociation. The redox property of Cu turned into a similar property of precious metals by managing the interaction between Cu particles and a substrate. The conversion efficiency of Ni-Cu alloy particles increased than each element alone. The Ni was oxidized faster than the Cu so as to maintain a metallic surface of Cu. These properties of Cu were incorporated into new design of a Cu catalyst, which has achieved high catalytic activity with the regular operation of engine in the beginning.