摘要
采用共沉淀法制备MoVTe复合氧化物系列催化剂,研究其一步氧化丙烯制备丙烯酸的催化性能,并采用XRD、ICP、EDS、H2-TPR、NH3-TPD对催化剂的结构、表面进行表征.结果表明,加入适量的Nb显著提高MoVTe复合氧化物对丙烯酸的选择性,可从34.1%提高至83.5%;同时丙烯酸的收率从24.7%提高到48.8%.适量Nb存在可以稳定催化剂表面Te元素,从而提高了丙烯酸的选择性;B、Fe、Ce、W元素掺杂对催化剂催化性能产生不同的影响,B掺杂提高了催化剂的催化性能,加入酸性元素硼可增加MoVTeNb复合氧化物催化剂表面丙烯活化位点(Te4+=O·Te3+─O·)的数目,使得丙烯转化率和丙烯酸收率显著提高,分别高达89.8%和64.8%.
MoVTe catalyst was prepared using co-precipitation method and its catalytic performance for one step o xidation of propylene to acrylic acid was then investigated. XRD,ICP,EDS,H2-TPR and NH3-TPD characterization techniques were applied to confirm the structures and surface properties of catalysts. Results showed that the appropriate amount of Nb doping could improve the selectivity of MoVTe catalyst for acrylic acid significantly, in which the selectivity and yield of acrylic acid were increased from 34. 1% and 24. 7% to 83. 5% and 48. 8% r espectively. This is because the Nb atom could enhance the stability of Te atom on the surface of the catalyst, which played an important role for producing acrylic acid. In addition,on the basis of Nb doping,B doping could increase the amount of active sites of Te4 += O·Te3 +─O·,which could subsequently increase the propylene conversion. Results showed the highest propylene conversion and yield of acrylic acid was 89. 8% and 64. 8%,r espectively.
出处
《分子催化》
EI
CAS
CSCD
北大核心
2014年第2期132-139,共8页
Journal of Molecular Catalysis(China)
基金
辽宁省'百千万人才工程'资助项目(2013921046)
关键词
丙烯
一步氧化
改性
催化剂
丙烯酸
propylene
one-step selective oxidation
doping
catalyst
acrylic acid
