Ce_(1-x)Y_xO_(2-δ)(x=0,0.15,0.25)纳米粉体的氧化-还原性能研究  

Research on redox property of Ce_(1-x)Y_xO_(2-δ)( x =0,0.15,0.25) nanopowder

作　　者：袁强[1] 甄强[1,2] 李榕[2] 谭威[2] 王太和[2] 

机构地区：[1]上海大学材料科学与工程学院,上海200072 [2]上海大学纳米科学与技术研究中心,上海200444

出　　处：《功能材料》2014年第17期17087-17093,共7页Journal of Functional Materials

基　　金：国家自然科学基金资助项目(51072112;51311130110);上海大学创新基金资助项目(sdcx2012033;sdcx2012062);上海市高校青年教师培养资助计划资助项目(B.37-0407-12-008);攀枝花市科技局产业推进资助项目(2012CY-S-18)

摘　　要：为了研究氧化铈（YDC）材料的氧化还原性能,通过水溶液体系中沉淀反应平衡的计算,研究了Y3＋、Ce3＋在水溶液体系中共沉淀的pH值条件,并制备了Ce1-xYxO2-δ（x=0,15%,25%）纳米粉体,平均晶粒尺寸在12 nm左右。通过O2-TPD研究了Ce1-x YxO2-δ纳米粉体在室温-1 000℃的氧气的脱附行为,发现随着Y2O3掺杂量增加,氧脱附峰面积增大,但脱附氧的起始温度提高,说明Y2O3的掺杂使样品中的氧空位增加,增加了氧的脱附量。通过H2-TPR研究了Ce1-xYxO2-δ纳米粉体在200-1 000℃条件下的氢气还原能力,发现随着Y2O3掺杂量增加,在450-650℃,Ce1-xYxO2-δ纳米粉体消耗H2峰强度逐渐增大,说明Ce1-xYxO2-δ的抗还原性能提高;在750-950℃,CeO2纳米粉体的消耗H2峰强度逐渐减小,说明CeO2抗还原的能力逐渐降低。通过O-1s和Ce3d XPS能谱分析结果可知,随着Y2O3掺杂量增加,Ce1-xYxO2-δ纳米粉体的晶格氧峰和吸附氧峰的强度降低,证明了在加热过程中,Ce1-xYxO2-δ的氧气脱附量逐渐增大;相对在空气条件下加热处理的样品,在10%H2/Ar混合气体条件下加热处理后,Ce1-xYxO2-δ纳米粉体中有部分的Ce4＋被还原为Ce3＋。To investigate the redox property of Ce1 -x Yx O 2 -δ（x =0,0.15,0.25 YDC）nanopowder,the YDC nanopowder with average crystal size around 12 nm was prepared by co-precipitation method.The pH value of Y3 ＋ ,Ce3 ＋ co-precipitation was studied in aqueous solution by calculation of precipitation equilibrium.Through the O 2-TPD study at RT-1 000 ℃,it was found that the oxygen desorption increased at higher initial oxidation temperature as results of oxygen vacancies increment and ceria reduction by Y2 O 3 doping.The reducing property of YDC was investigated by H 2-TPR at 200-1 000 ℃.The Y2 O 3 dopant enhanced the anti-reducing property of YDC at 450-650 ℃.While the H 2 consumption peak decreased with the Y2 O 3 dopant increased at 750-950 ℃, the results suggested the decrease of YDC reducing property.Compared the O1s and Ce3d spectrums of XPS results,the peaks of lattice oxygen and oxygen desorption increased with the Y2 O 3 dopant increased,that showed the oxygen desorption of Ce1 -x Yx O 2 -δ nanopowder increased in the heating process.And it was found that Ce4＋was partly transformed to Ce3 ＋ by Y2 O 3 doping after heat treatment at air or 10%H 2/Ar atmosphere.

关 键 词：CEO2 Y2O3 氧化还原 纳米粉体 

分 类 号：TQ132.35[化学工程—无机化工]