| V-Ag-Ni系氧化物的表面氧性质与甲苯选择性氧化的催化性能 |
| NATURES OF OXYGEN SPECIES ON THE SURFACES OF V-Ag-Ni OXIDES AND CATALYTIC ACTIVITIES FOR THE SELECTIVE OXIDATION OF TOLUENE |
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| 摘要: 制备了一系列V、Ag、Ni原子比不同的三元氧化物,应用TPD-MS技术研究了样品表面氧的性质,并测定了甲苯选择性氧化生成苯甲醛的催化活性。实验结果表明,样品表面存在有多种吸附的氧物种。在脱附温度<900℃:当Ni含量对Ag(或V)的原子比为0.25或0.50时,仅在低温处出现有表面的O-和O2-两种氧物种的脱附峰；当Ni含量对Ag(或V)的原子比增高到>0.75时,除有表面的O-和O2-两种氧物种的脱氧峰外,还有由于样 |
| 关键词: V-Ag-Ni氧化物 甲苯选择性氧化 表面氧性质 |
| 基金项目: 中国科学院基金;南京大学现代分析中心测试基金 |
| Abstract: A series of V-Ag-Ni trioxides with various atomic ratios of V, Ag and Ni were prepared.The catalytic activities for the selective oxidation of toluene to benzaldehyde were obtained, and the natures of oxygen species on the surfaces of these samples were studies by using temperature programmed desorption-mass spectrography(TPD-MS). The results showed that the oxygen species of multiple adsorption existed on the sample surface. And in the range of desorption temperature < 900℃: for the samples in which the content of nickel versus Ag (or V) with atomic ratio equaled 0.25(or 0.50), the desorption peaks of the SPecies of surface O- and O2- appeared near the lower temperatures; for the samples in which the atomic ratio of nickel versus Ag (or V) was increased to a value of 0.75, not only the desorption peaks of O- and O2- species on surfaces of samples occurred, but also the O2- spedes of lattice appeared due to the phase transformations in the samples. As the content of Ni in V-Ag oxide was changed. the activation energy of oxygen desorption (Ed)also changed. The Ed value of 3# sample (V: Ag : Ni = 1: 1: 0.75) is the lowest, the selectivity of benzaldehyde in toluene oxidation is the highest. Thus, a parallel relation between the Ed value and the selectivity for benzaldehyde existed in these V-Ag-Ni oxides. |
| Keywords: V-Ag-Ni oxide selective oxidation of toluene natures of oxygen species of surface |
| 投稿时间：1993-05-06 |
| 摘要点击次数: 1154 |
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| 上官荣昌,张惠良,葛欣,洪建明.V-Ag-Ni系氧化物的表面氧性质与甲苯选择性氧化的催化性能[J].无机化学学报,1994,10(2):194-198. |
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