Self-Regeneration Effect of Three-Way Catalysts during Thermal Aging Procedure

Catalysts

AlekseyA. Vedyagin¹  KonstantinV. Bubnov²  SergeyP. Denisov²  EvgenyA. Alikin² 

[1] Department of Materials Science and Functional Materials, Boreskov Institute of Catalysis SB RAS, Novosibirsk 630090, Russia;Research & Development Department, Ecoalliance Limited Liability Company, Novouralsk 624131, Russia;

关键词: three-way catalysts;    rhodium;    engine bench;    high-temperature aging;    self-regeneration;   

DOI  :  10.3390/catal10111257

来源: DOAJ

【 摘 要 】

One of the most important features of the three-way catalysts is their long-term stability. However, quite often, promising catalytic compositions with excellent activity become deactivated after a relatively short period of exploitation due to various reasons. Therefore, a study on the onboard regeneration of the deactivated three-way catalysts remains its actuality. The present work is mainly focused on the self-regeneration effect of the rhodium-containing component. Aging of the catalysts in the standard and model engine braking regimes revealed the difference in the catalytic performance. Deactivated rhodium species turned to the active state as a result of rapid cooling in air flow from 1200 to 600 °C. The regenerated catalyst shows improved activity towards NO_x reduction and, therefore, widened operation window, which indicates higher accessibility of the rhodium species. X-ray diffraction analysis of the aged catalysts does not reveal any noticeable phase changes. Contrary, significant changes in the Rh oxidation state were registered by X-ray photoelectron spectroscopy. The observed effect opens new horizons for the development of the onboard purification systems with prolonged exploitation lifetime.

【 授权许可】

Unknown