Study of OSC materials from the viewpoint of catalyst deterioration on-board diagnosis

Akhmad Fadel Fadilla･Masami Nakamoto･Dai Sawada･Tetsuro Onishi･Kazuya Yasuda (DAIHATSU MOTOR)･Yuki Kazama･Shunsuke Oishi･Takashi Goto (CATALER)･Daiju Matsumura (Kwansei Gakuin University, Japan Atomic Energy Agency)･Hirohisa Tanaka (Kwansei Gakuin University)

Catalyst degradation is diagnosed by monitoring the OSC (Oxygen Storage Capacity) of the catalyst.
In order to correctly diagnose catalyst deterioration, which is required to be more accurate due to stricter regulations, we studied the improvement of the OSC expression rate in relation to the amount of Ce input.
By lowering the CZ ratio of the OSC material, the valence change of Ce became faster, and the OSC expression rate improved.
We also confirmed an improvement in the purification rate.

High Performance DPF to Tackle Nano Particulate Emissions for Off-Highway Applications

Shotaro Kato･Hiroaki Suzuki･Ryuji Kai･Takashi Aoki (NGK Insulators)

Diesel Particulate Filters (DPFs) have been widely used for PM/PN reduction in diesel applications. With the upcoming Tier 5 and EU Stage VI regulations, including stricter PM/PN limits and potential CO₂ targets, NGK developed DPFs using Cordierite (Cd) and Silicon Carbide (SiC) with various cell structures. Engine testing was conducted to evaluate filtration efficiency and pressure drop across filters with different mean pore sizes. The results identified optimal DPF configurations that support a common aftertreatment system for future global emission compliance.

PN10 Emission Behavior in Diesel Engines

Hiroshi Anoda･Haruki Goto･Genshirou Shibuya (Isuzu Motors)･Igor Gershkovich･Mojtaba Keshavarz (Isuzu motors germany)

In the next European Emission Regulation Euro7, the PN (Particulate Number) regulation will be strengthened, and the target particle size will be expanded from 23 nm or more to 10 nm or more. It is important to understand the PN10 emission behavior. This paper reports the results of investigation of PN10 emission behavior in a diesel engine.

Improvement of performance of catalyst-coated gasoline particulate filter by controlling catalyst density

Tomoya Takizawa･Hiroyuki Kurita･Takashi Araki･Kohei Sakai･Hiroshi Murakami (Mazda)

This research aimed to improve the PN filtration efficiency of catalyst-coated gasoline particulate filter without worsening pressure loss. In this report, characterizing the relationship between the density of the catalyst coated on substrate and above perfoemance, we revealed design concept of catalyst-loaded gasoline particulate filter for higher PN filtration, lower pressure drop, and higher three-way purification perfoemance.

Study on Factors of Performance Degradation of Urea SCR System Installed in Heavy Duty Vehicles during the Use Process

Toshiro Yamamoto (NALTEC)

Data on the NOx reduction performance of urea SCR systems (copper-based catalyst) installed in vehicles that comply with the 2016 exhaust gas regulations was collected continuously by conducting chassis dynamometer tests etc. as the cumulative mileage increased. Based on this, the factors that affect the exhaust gas reduction performance of the urea SCR system during use were analyzed, and the actual performance degradation was grasped. During use, a decrease in the SCR catalyst gas temperature was confirmed, which coincided with a downward trend in the NOx purification rate and was therefore considered to be factors in the deterioration of performance.

Effect of Ambient Humidity on Nitrous Oxide Emissions from Light Duty Vehicles

Shoi Koshikawa･Hisakazu Suzuki (Automobile and Land Transport Technology)

Ambient conditions around a vehicle affect the emission characteristics from the vehicle. Nitrous oxide (N2O), which has a high global warming potential, has been reported to have emission characteristics under various temperature conditions, but humidity has not been focused on. In this report, the effect of ambient humidity on N2O emissions from a gasoline vehicle was investigated using a chassis dynamometer.

High Porosity Substrate for PHEV

Daiki Suzuki･Takashi Aoki･Tasuku Matsumoto･Yuji Sasaki･Kai Matsumoto (NGK Insulators)

For Tier 4 regulations in the US, the NMOG+NOx emission limits will become tighter. In particular, plug-in hybrid electric vehicles (PHEVs) may experience emission deterioration during the switch from EV mode to engine mode, making improvements to the aftertreatment system a key challenge. The high porosity substrate is expected to reduce emissions during cold starts, and this paper presents the evaluation results of such an approach.