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This paper describes a new catalyst powder has been developed that provides cleaner exhaust emissions and reduces the consumption of precious metals. In recent years, precious metal usage has been increasing due to the tightening of emission regulations and the increase in automobile production worldwide. Minimizing the use of precious metals in exhaust catalysts is crucial not only for reducing the cost of vehicles but also for effective utilization of scarce resources. Iron is one of the alternative material candidates for precious metals. It was found that the Iron catalyst was activated by iron becoming the low oxidation state while iron oxide and cerium oxide synchronized in a nanostructure interface. A catalyst with improved iron support technology that enables better contact between highly dispersed particles of iron and ceria was found to exhibit higher exhaust gas cleansing performance than precious metal catalysts even after aging.

Particulate matter (PM) including soot in diesel exhaust gas is a serious atmospheric pollutant, and stricter exhaust emission standards are being set in many countries. As one of the key technologies, a diesel particulate filter (DPF) for PM trap in the after-treatment of the exhaust gas has been developed. Typically, the inlet size of filter monolith is about 2 mm, and the thickness of the filter wall is only 0.2 mm, where soot particles are removed. It is impossible to observe the small-scale phenomena inside the filter, experimentally. Then, in the present study, we conducted microfluidic simulation with soot oxidation. Here, a real cordierite filter was used in the simulation. The inner structure of the filter was scanned by a 3D X-ray CT Computed Tomography) technique. The advantage is that it is non-intrusive system, and it has a high spatial resolution in the micrometer.

This paper describes a newly developed NOx trap catalyst that achieves cleaner exhaust gas using much smaller quantities of precious metals. The precious metal loading of this NOx trap catalyst has been halved by developing a technique for inhibiting precious metal sintering even under exposure to high temperature exhaust gas and a trap material with improved catalyst functions at low temperature. This NOx trap catalyst is used on the Nissan X-TRAIL fitted with a diesel engine, which was the first vehicle to comply with Japan's Post New Long term Exhaust Emission Regulations.