镧、锰共掺杂改性CeO2-ZrO2-Al2O3固溶体的性能

摘要

A series of CeO2-ZrO2-Al2O3 (CZA) materials was prepared by the co-precipitation method and characterized by specific surface area measurements ( BET), X-ray diffraction ( XRD), H2 -temperature-programmed reduction (H2-TPR ), X-ray photoelectron spectroscopy (XPS) and X-ray fluorescence (XRF ). The results showed that these successfully-prepared CZA solid solutions had an optimum textural performance after calcinations at 600 ℃ for 3 h and the support sample of doping La and Mn together still possessed the high thermal stability. According to the H2-TPR, the sample modified by La and Mn showed the best property of reducibility at low temperature. XPS results indicated that by doping La, the transfer of Mn from the bulk to the surface in calcinations was restrained and the concentration of adsorbed oxygen was retained.%采用共沉淀法制备了一系列La,Mn共掺杂的CeO2-ZrO2-A12O3 (CZA)复合氧化物,采用BET,XRD,H2 -TPR,XPS和XRF等方法对样品进行表征.结果表明,全部样品均形成了稳定的CZA固溶体,经600℃焙烧后表现出良好的织构性能,1000℃老化后,La,Mn共掺杂样品具有最佳的高温稳定性；H2-TPR测试表明,La,Mn之间存在正协同效应,共掺杂的样品具有最佳的低温还原性能和高温稳定性；XPS结果表明,掺杂La可有效抑制在焙烧过程中Mn向表面的迁移,从而保持较高的表面吸附氧浓度.