掺杂钇铋Ce-Zr-Al储氧材料的制备及性能研究

Preparation and Property of Ce-Zr-Al Oxygen Storage Materials Modified by Y^(3+) and Bi^(3+) Addition

采用共沉淀法制备了掺杂Y3+、Bi3+的CeO2-ZrO2-Al2O3(CZA)储氧材料,并通过XRD、低温N2吸附-脱附、氧脉冲吸附(OSC)及H2-TPR等手段进行了表征.XRD结果表明,600℃和1000℃焙烧后,Y3+、Bi3+的加入没有改变物相结构,所有样品均形成单一立方相萤石结构固溶体.低温N2吸附结果表明,Y3+掺杂的Ce0.6Zr0.3Y0.1O1.95-Al2O3(CZYA)材料,其织构性能及热稳定性都有很大的改善,1000℃老化5h后,比表面积和孔容可分别达80.75m2/g和0.22mL/g.OSC和H2-TPR结果表明,同时掺杂Y3+、Bi3+的Ce0.6Zr0.2Y0.1Bi0.1O1.9-Al2O3(CZYBA)材料,其储氧性能明显增强,经600和1000℃焙烧后分别达到461和242μmol/g;同时掺杂Y3+、Bi3+增强了CZA材料的还原性能,1000℃老化5h后还原峰温度从546℃降低到429℃.

A series of CeO2-ZrO2-Al2O3 oxygen storage materials were prepared by co-precipitation method and characterized by means of X-ray diffraction（XRD）,low temperature nitrogen adsorption-desorption,oxygen storage capacity（OSC） and H2-temperature programmed reduction（H2-TPR）.The results of XRD show that the phase structure of CZA are not changed by the addition of Y^（3＋） and Bi^（3＋）,and all samples remain the single cubic fluorite structure after calcination at 600℃ and 1000℃.According to the results of low temperature nitrogen adsorption,the textural properties and thermal stability of Ce0.6Zr0.3Y0.1O1.95-Al2O3（CZYA）make a great progress after the introduction of Y^（3＋）,and after calcination at 1000℃ for 5h,specific surface area and pore volume of CZYA achieve 80.75m2/g and 0.22mL/g,respectively.The results of OSC and H2-TPR show that co-doping Y^（3＋） and Bi^（3＋） into CZA exhibit positive effect on OSC of the materials.The OSC of Ce0.6Zr0.2Y0.1Bi0.1O1.9-Al2O3（CZYBA）calcinated at 600℃ and 1000℃ reach 461μmol/g and 242μmol/g,respectively.Meanwhile the redox property of CZYBA is enhanced,the reduction peak temperature can be reduced from 546℃ to 429℃ after calcination at 1000℃ for 5h.