Effect of Difference in Oxygen Storage State of Pd/CeO₂-ZrO₂ Three-Way Catalyst on Oxygen Storage Distribution

Yuki Watanabe･Yuma Hayashi･Tsuyoshi Nagasawa･Susumu Sato･Hidenori Kosaka (Institute of Science Tokyo)･Hiroyuki Itoyama･Chengwei Huang (Nissan Motor)

In order to clarify the oxygen storage and release mechanism of three-way catalysts (TWC), visualization experiments of the oxygen storage distribution were conducted using isotope quench technique. In this technique, oxygen isotope labeling, and reaction quenching are conducted, then isotope distribution is measured by secondary-ion mass spectrometry. In this report, visualization experiments were conducted using a model catalyst consisting of dense ceria-zirconia disk and Pd to clarify the effect of the difference in oxygen release/storage states on the oxygen storage distribution by changing the hydrogen reduction time and oxygen storage time.

The Effect of Stored Oxygen on Purification Performance of Three-way Catalysts under Perturbation Condition

Sota Aoyama･Jin Kusaka (Waseda University)

The effect of oxygen storage capacity on the purification performance of three-way catalysts was experimentally analyzed by conducting tests incorporating perturbations using catalysts with oxygen storage capacity. In the test results, the purification performance characteristics with and without catalyst degradation were clarified by focusing on the decrease in purification rate for each gas type and the change in oxygen concentration at the inlet and outlet.

Verification of Temporary Poisoning Mechanism in Automotive Catalysts by HC Components

Hiroyuki Minokoshi･Daichi Tabuchi･Ryo Nagai (SUBARU)･Masaaki Haneda (Nagoya Institute of Technology)

Performance of automotive catalysts temporarily deteriorates after HC components in exhaust gas attach to the catalysts. We studied HC type and attachment site to the catalysts to verify the mechanism of temporary poisoning. As a result, we found that exhaust gas contained a high proportion of specific types of aromatic HC. In addition, we found that catalytic performance deteriorated after these types of aromatic HC attached to the boundaries between platinum group metals and CZ materials.

Study of an Exhaust System for 100% Electric Drive Hybrid Vehicles that Achieves Well-to-wheel Exhaust Emissions Comparable to Electric Vehicles
-The Challenge Towards Zero Emissions-

Akira Inoue･Hiroyuki Itoyama･Atsushi Morohoshi･Jin Yokoyama (Nissan Motor)

Internal combustion engines for electric hybrid vehicles are required to respond to stricter emission regulations, CO2 reduction, and fluctuations in material markets.
The advantages and disadvantages of catalyst warm-up were examined in multiple systems, and the possibility of achieving electric vehicle-level exhaust emissions (WTW), reducing CO2 , and the amount of precious metals in the catalyst was examined through both simulations and experiments for ceramic EHC, which has high compatibility with 100% electric drive hybrid systems.