Ce_1-xLa_xO_y solid solution prepared from mixed rare earth chloride for soot oxidation

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• 作者：Xue HAN (韩 雪)^a ; ^{hanxuehit@126.com" class="auth_mail" title="E-mail the corresponding author} ; Yafei WANG (王亚飞)^b ; Hongrui HAO (郝红蕊)^a ; Ronggui GUO (郭荣贵)^a ; Yunsheng HU (胡运生)^a ; Wenquan JIANG (蒋文全)^a
• 关键词：Ce1&ndash ; xLaxOy solid solution ; soot oxidation ; mixed rare earth chloride ; ultrasonic-assisted method ; co-precipitation
• 刊名：Journal of Rare Earths
• 出版年：2016
• 出版时间：June 2016
• 年：2016
• 卷：34
• 期：6
• 页码：590-596
• 全文大小：1010 K

文摘

Ce_1–xLa_xO_y solid solution was simply prepared using mixed rare earth chloride (RECl₃·xH₂O, RE=Ce, La>99%, containing unseparated Ce and La from rare earth metallurgical industry) as precursor by ultrasonic-assisted co-precipitation method with different ultrasonic frequencies (CLf, f=200, 400, 600, 800, 1000 Hz). A compared Ce_1–xLa_xO_y solid solution (CL^*) was also prepared by the same mothod with 10% less precipitant. X-ray diffraction results confirmed the formation of Ce_1–xLa_xO_y solid solution, and the crystal structures of these catalysts were not very sensitive to ultrasonic frequency and precipitant amount. However, both of the factors had obvious effect on morphology and surface area of CL, and precipitant amount seem to play a more crucial role than ultrasonic frequency for Ce_1–xLa_xO_y solid solution preparation. When soot and catalyst were tight contacted, the peak temperature (T_peak) of soot oxidation and oxygen reducing temperature for CLf catalysts decreased linearly with increasing surface area. Under loose contact condition, the T_peak had obvious negative correlation with H₂ consumption. It was inferred that good reducibility of the Ce_1–xLa_xO_y solid solution favored the soot oxidation reaction. The Ce_1–xLa_xO_y solid solution prepared from unseparated rare earth chloride showed a good soot oxidaiton activity. Controlling the preparation conditions to prepare a CL catalyst would high surface area will enhance its reducibility and activity.