(1. 湖南科技大學(xué) 化學(xué)化工學(xué)院，湘潭 411201；
2. 中南大學(xué) 粉末冶金研究院，長沙 410083)
摘 要: 分別以檸檬酸(CA)、聚乙二醇(PEG)和淀粉(ST)為添加劑，采用共沉淀法制備CeO2-ZrO2-Al2O3(CZA)復(fù)合氧化物儲氧材料，利用XRD、TG/DSC、SEM、N2吸附-脫附、氧脈沖吸附和程序升溫還原等檢測方法對材料性能進(jìn)行表征。XRD結(jié)果表明:ST添加劑的樣品經(jīng)1000 ℃煅燒后產(chǎn)物主要為CeO2和γ-Al2O3，添加CA與PEG的樣品為CeO2-ZrO2相，并夾帶少量γ-Al2O3相；經(jīng)1100 ℃煅燒后，3種添加劑樣品都主要為CeO2-ZrO2晶相。SEM結(jié)果表明:CA、ST和PEG添加劑樣品經(jīng)1000 ℃高溫處理后，分別為顆粒狀、蜂窩狀和多孔網(wǎng)狀結(jié)構(gòu)。N2吸附-脫附結(jié)果表明:經(jīng)600 ℃熱處理后，ST添加劑樣品具有最大的比表面積234.95 m2/g和孔容1.589 cm3/g；經(jīng)1000 ℃熱處理后，添加PEG樣品獲得最大的比表面積、孔容和孔徑，其值分別為92.50 m2/g、0.702 cm3/g和29.84 nm，且有最佳的孔分布和吸附-脫附能力。儲氧性能OSC和H2-TPR結(jié)果表明:PEG添加劑制備的材料具有最好的儲氧能力(OSC)和還原性能；1100 ℃高溫下，ST添加劑樣品的結(jié)構(gòu)特性與PEG的接近；而CA添加劑樣品的吸附能力、儲氧性能都相對較低。
關(guān)鍵字: CeO2-ZrO2-Al2O3；儲氧材料；添加劑；結(jié)構(gòu)；性能
（1. School of Chemistry and Chemical Engineering, Hunan University of Science and Technology,
Xiangtan 411201, China;
2. College of Powder Metallurgy, Central South University, Changsha 410083, China）
Abstract:CeO2-ZrO2-Al2O3 oxygen storage materials were prepared by coprecipitation method using citric acid (CA), starch (ST) and polyethylene glycol (PEG) as organic additives. The material performances were characterized by X-ray diffraction (XRD), TG/DSC, SEM, N2 adsorption-desorption, oxygen pulse adsorption and H2 temperature -programmed reduction (H2-TPR). The XRD results show that the sample with starch-additive has CeO2 and γ-Al2O3 phases, while the samples with citric acid and polyethylene glycol additives mainly have CeO2-ZrO2 cubic fluorite and only a little γ-Al2O3 phases after sintered at 1000 ℃. The samples are major CeO2-ZrO2 solid solution crystal phase with three additives after sintered at 1100 ℃. The SEM results display that the products are particulate with citric acid additive, the products are honeycomb with starch additive, and the products are porous with polyethylene glycol additive. The N2 adsorption-desorption results demonstrate that the sample facilitated by starch additive has the largest specific surface area of 234.95 m2/g, highest pore volume of 1.589 cm3/g after sintered 600 ℃. When sintered at 1000 ℃, the sample by polyethylene glycol additives-modified method possesses the largest specific surface area (92.50 m2/g), pore volume (0.702 cm3/g) and pore diameter (29.84 nm), the best pore size distribution and adsorption-desorption capacity. The results of oxygen storage and H2-TPR indicate that the samples prepared with polyethylene glycol additives have the best oxygen storage performance (OSC) and reduction capacity. The structural characteristics of the samples calcined at 1100 ℃ with starch additive exhibit proximity to that of samples prepared with polyethylene glycol additives. The samples synthesized with citric acid additive show relatively lower adsorption and oxygen storage performance.
Key words: CeO2-ZrO2-Al2O3; oxygen storage material; additive; structure; performance
