Ultrasonic-assisted fabrication and catalytic activity of CeZrAl oxide-supported Pd for the purification of gasohol exhaust

CeZrAl oxides (CZA) using as the support of Pd catalyst for purification of gasohol exhausts are synthesized by co-precipitation assisted by ultrasonic vibration. CZA are characterized by surface analysis, X-ray diffraction, temperature-programmed reduction by hydrogen, oxygen storage capacity (OSC), and X-ray photoelectron spectroscopy. The results show that ultrasonic vibration promotes the formation of smaller, more uniform pores in CZA, which is beneficial to the dispersion of Pd species. Ultrasonic vibration can also improve the OSC and uniformity of the composition of CZA on its surface and in bulk. Catalytic tests demonstrate that ultrasonic treatment of CZA widens the window of the full use of oxygen from 0–0.64% to 0–1.16% of Pd-CZA catalysts in the purification of gasohol exhaust, and decreases the light-off temperature of ethanol, propane, and carbon monoxide by 30, 28, and 24 °C, respectively. Moreover, the interaction between Pd species and CZA can enhance the reaction of NO with propane and ethanol.

摘要在共沉淀法的基础上辅助以超声制备了铈锆铝复合氧化物 14;(CZA), 14;采用比表面分析仪、X 14;射线衍射、程序升温还原、储氧量和 14;X 14;射线光电子能谱对材料进行了表征. 结果表明, 14;超声振荡有助于小而均匀的孔生成, 14;有利于 14;Pd 14;物种的分散; 超声振荡还能提高 14;CZA 14;的储氧量, 14;使材料的表面组成与体相组成趋于一致. 催化活性测试表明, 14;材料经过超声处理的 14;Pd-CZA 14;净化乙醇汽油车尾气时, 14;可以将氧气的完全利用窗口从 14;0∼0.64% 14;拓宽至 14;0∼1.16%; 并且使乙醇、C3H8 14;和 14;CO 14;起燃温度分别下降了 14;30, 14;28 14;和 14;24 14;°C. 此外, 14;Pd 14;物种与 14;CZA-U 14;的相互作用有利于 14;NO 14;与 14;C3H8 14;和 14;C2H5OH 14;的反应.

Ultrasonic vibration leads to more Ce on the surface of a CeZrOx solid solution, and therefore more Pd species that interact with Ce.Figure optionsDownload as PowerPoint slide