摘要
To investigate the changes of the physicochemical properties of the three-way catalytic converter (TWC) for automotive engines under high temperature hydrothermal conditions,the samples were subjected to hydrothermal aging treatment using a rapid hydrothermal aging device at different temperatures and air velocities,as well as N2 physical adsorption,X-ray diffraction (XRD),X-ray photoelectron spectroscopy (XPS),transmission electron microscopy (TEM) and other microscopic characterization tests. The results show that with the increase of temperature the specific surface area decreases sharply, the pore volume decreases,the pore size increases,the CeO2 particle size increases,and the physical structure of the catalytic pore channel shows a certain degree of collapse. By increasing the aging temperature,the chemical properties such as oxygen storage capacity change significantly,which is manifested in the decrease of the relative content of Ce3+. Compared with the temperature,the change of air velocity has less effect on the physical structure of the catalytic converter,and the relative content of Ce3+ increases during the increase of air velocity and the oxygen storage capacity is enhanced. It can be seen that temperature is the main factor of catalytic converter degradation and deactivation during the hydrothermal treatment. ? 2023 Chinese Society for Internal Combustion Engines.
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