催化学报

催化学报 ›› 2008, Vol. 29 ›› Issue (12): 1277-1282.

• 研究论文 • 上一篇    下一篇

甲烷氧化偶联纳米SrTiO3催化剂的原位ESR和TPSR表征

缪建文1,3,宋国华2,范以宁3,周静3   

  1. 1 南通大学化学化工学院, 江苏南通 226001; 2 南通大学理学院, 江苏南通 226001; 3 南京大学化学化工学院, 江苏南京 210093
  • 收稿日期:2008-12-25 出版日期:2008-12-25 发布日期:2012-09-20

Characterization of Nanosized SrTiO3 Catalyst for Oxidative Coupling of Methane by in Situ ESR and TPSR

MIAO Jianwen1,3*, SONG Guohua2, FAN Yining3, ZHOU Jing3   

  1. 1 School of Chemistry and Chemical Engineering, Nantong University, Nantong 226001, Jiangsu, China; 2 School of Science, Nantong University, Nantong 226001, Jiangsu, China; 3 School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210093, Jiangsu, China
  • Received:2008-12-25 Online:2008-12-25 Published:2012-09-20

PDF

892

被引次数

3

摘要： 采用溶胶-凝胶法制备了纳米钙钛矿型复合氧化物SrTiO3催化剂,并用X射线粉末衍射、透射电子显微镜、原位电子自旋共振和程序升温表面反应等技术对催化剂进行了表征,测定了催化剂对甲烷氧化偶联(OCM)反应的催化性能. 结果表明,与相同组成的常规SrTiO3催化剂相比,纳米SrTiO3催化剂具有较好的低温(～650 ℃)催化性能. 通过增大Sr/Ti比可进一步优化纳米SrTiO3的催化性能. 纳米SrTiO3催化剂表面的吸附氧物种和F中心均具有活化及催化甲烷分子生成C2烃产物的活性,但吸附氧物种易使OCM反应中间体和产物深度氧化,而F中心具有低温活化甲烷分子及高选择性生成C2烃产物的特性. 纳米氧化物粒子因表面原子配位不饱和(配位数低), 其表面存在较多的F中心.

关键词: 甲烷, 氧化偶联, 钛酸锶, 纳米催化剂, 电子顺磁共振, F中心, 程序升温表面反应

Abstract: The catalytic performance of nanosized SrTiO3 (n(Sr)/n(Ti)=1.2) a nd conventional SrTiO3 (n(Sr)/n(Ti)=1.2) for OCM reaction was mea sured. The nanosized SrTiO3 catalyst exhibited better catalytic activity at l ow temperature (～650 ℃) than the conventional SrTiO3 catalyst with the sam e composition. The catalytic performance of the nanosized SrTiO3 catalyst was correlated to the higher concentration of F centers owing to low coordination nu mbers on the nanosized oxide particles.

Key words: methane, oxidative coupling, strontium titanate, nanocatalyst, electron spin resonance, F center, temperature-programmed surface reaction