A new insight into the role of transition metals doping with CeO2–ZrO2 and its application in Pd-only three-way catalysts for automotive emission control

• Published in: Fuel (Guildford) 2012-02, Vol.92 (1), p.360-368
• Main Authors: Li, Guangfeng, Wang, Qiuyan, Zhao, Bo, Zhou, Renxian
• Format: Article
• Language: English
• Subjects: Applied sciences; CeO2–ZrO2; Dynamic oxygen mobility; Energy; Energy. Thermal use of fuels; Exact sciences and technology; Fuels; In situ Raman; Pd-only three-way catalysts; Transition metals
• ISSN: 0016-2361; 1873-7153
• DOI: 10.1016/j.fuel.2011.07.028

[Display omitted] ► The introduction of Fe or Co promotes the surface atom ratios of Ce/Zr. ► The introduction of Fe or Co makes the part of Ce4+ transferred into Ce3+. ► The increasing of oxygen vacancies for CZFe leads to the enhancement of DOSC. ► Pd/CZFe and Pd/CZCo are active in promoting the three-way catalytic performance. CeO2–ZrO2 (CZ) doped with different transition metals was prepared through a co-precipitation and supercritical drying method and the corresponding Pd-only TWCs were characterized. Pd/CZFe and Pd/CZCo exhibit the best catalytic activity and the widest operation window, in accordance with the decrease of the light-off and full-conversion temperature. However, Pd/CZCr restrains the catalytic property. It may be due to the different effect of transition metals on the property of CZ. The introduction of Fe and Co promotes the surface atom ratios of Ce/Zr, makes part of Ce4+ transferred into Ce3+ in order to maintain the electrical neutrality and seems to facilitate the reduction of Ce4+→Ce3+ or the formation of oxygen vacancies of CZ. The increasing concentration of oxygen vacancies for CZFe leads to the enhancement of DOSC. Moreover, the introduction of Fe favors the transfer of oxygen in different atmospheres.