Juji Suzuki

Development of a New DPNR Catalyst

We, at Toyota, have been working to develop a new DPNR (Diesel Particulate-NOx Reduction) system to decrease both PM and NOx emissions by combining the NOx storage-reduction catalyst for direct injection gasoline engines with the most advanced engine control technologies. The purpose of the DPNR catalyst is to decrease PM and NOx in order to purify automotive exhaust gas. To reduce PM emissions, the PM trapping rate and PM oxidizing performance must be improved. Since the deposition of PM increases the pressure drop across the catalytic converter, it should also be suppressed. To attain these objectives, we have\ developed a new DPNR catalyst by the adoption of a new porous substrate structure and the improvement of the catalyst coating technique. The new DPNR catalyst will be mounted on the Avensis for commercial use in the European market.

Development of Three-way Catalyst Using Composite Alumina-Ceria-Zirconia

Abstract To realize the high performance of the three-way catalyst, a new catalytic promoter. “ACZ” was proposed. ACZ consists of nanometer-size CeO2-ZrO2 solid solution (CZ) particles and diffusion barrier layers made of alumina (A) among the CZ particles. The specific surface area of ACZ was larger than that of the conventional CZ after durability test. The sintering of Pt on the ACZ-added catalyst is inhibited and the crystal size of CZ in the ACZ-added catalyst is smaller than that in the CZ-added catalyst. The dynamic OSC and the light off temperature of the ACZ-added catalyst are improved.

91 Development of three-way catalyst using composite alumina-ceria-zirconia

To realize the high performance of the three-way catalyst, a new catalytic promoter. “ACZ” was proposed. ACZ consists of nanometer-size CeO2-ZrO2 solid solution (CZ) particles and diffusion barrier layers made of alumina (A) among the CZ particles. The specific surface area of ACZ was larger than that of the conventional CZ after durability test. The sintering of Pt on the ACZ-added catalyst is inhibited and the crystal size of CZ in the ACZ-added catalyst is smaller than that in the CZ-added catalyst. The dynamic OSC and the light off temperature of the ACZ-added catalyst are improved.