(北京有色金屬研究總院 有研稀土新材料股份有限公司, 北京 100088)
摘 要: 采用共沉淀-水熱聯(lián)合法制備了大比表面鈰鋯復(fù)合氧化物材料, 在較低焙燒溫度400 ℃下形成了穩(wěn)定的晶相結(jié)構(gòu), 500 ℃焙燒新鮮比表面達(dá)135.44 m2/g, 900 ℃、 6 h老化后比表面仍維持44.07 m2/g。 采用沉淀-陳化工藝, 并摻雜改性, 得到的鈰鋯復(fù)合氧化物, 穩(wěn)定性更高, 經(jīng)950 ℃、 2 h老化后, 最高比表面可達(dá)59.62 m2/g。 活性氧化鋁與鈰鋯復(fù)合氧化物有協(xié)同作用, 二者復(fù)合得到了更高性能的氧化物材料, 新鮮比表面為188.92 m2/g, 經(jīng)950 ℃、 4 h老化后, 比表面為71.64 m2/g, 經(jīng)1 050 ℃、 4 h老化后, 比表面為58.10 m2/g。 對(duì)所得鈰鋯材料進(jìn)行了X射線衍射、 吸脫附表征, 并負(fù)載鈀貴金屬制得催化材料, 以甲烷完全催化燃燒為探針反應(yīng), 研究了鈰鋯復(fù)合氧化物材料的甲烷燃燒催化性質(zhì)。 結(jié)果表明, 鈰鋯復(fù)合氧化物材料是很好的燃燒催化劑二載材料, 負(fù)載鈀催化劑具有較高催化活性, 起燃溫度降低至352 ℃。
關(guān)鍵字: 鈰鋯復(fù)合氧化物； 高比表面； 高溫穩(wěn)定性； 甲烷催化燃燒
and its methane catalytic combustion
ZHANG Shun-li, HUANG Xiao-wei
（Grirem Advanced Materials Co., Ltd.,
General Research Institute for Nonferrous Metals, Beijing 100088, China）
Abstract: The cerium zirconium mixed oxides with high performance such as high surface area, good thermal stability were prepared by the method of co-precipitation and hydrothermal treatment. The stable crystal phase was formed under low temperature of 400 ℃, the surface area of fresh sample calcined at 500 ℃ is up to 135.44 m2/g, and the surface area of aged sample calcined at 900 ℃ for 6 h is 44.07 m ℃/g. The more thermal stable cerium zirconium mixed oxide powders were obtained by the process of co-deposition and hot aging, and by the technology of Al3+ doping modification, whose highest surface area of aged samples at 950 ℃ for 2 h is up to 59.62 m2/g. The superior mixed oxide is formed with the active alumina introduction into cerium zirconium mixed oxides, whose fresh surface area is 188.92 m2/g, aged sample at 950 ℃ for 4 h is 71.64 m2/g, and aged sample at 1 050 ℃ for 4 h is 58.10 m2/g. The mixed oxides was characterized by means of X-ray diffraction, adsorption and de-sorption. The cerium zirconium catalyst was obtained by palladium metal impregnation techniques. With methane catalytic combustion as probe reaction, the catalytic activity of cerium zirconium mixed oxides was studied, and the results show that cerium zirconium mixed oxides is a good carrier of support for combustion catalysts. The catalytic activity of palladium supported cerium zirconium catalyst is high, whose light-off temperature is as low as 352 ℃.
Key words: cerium zirconium mixed oxides; high surface area; good thermal stability; methane catalytic combustion
