摘要
对不同Sb/Fe比,500℃焙烧的样品,采用了X射线衍射、穆斯堡尔谱、比磁化强度、红外光谱、表面微区元素分析及甲苯氧化生成苯甲醛的活性测定等进行了研究。结果表明,在催化剂的表面上均有锑富集,锑的比富集量愈大,苯甲醛的选择性也愈高。不含铁样品的物相为Sb_2O_4,生成苯甲醛的选择性最高。当Sb/Fe=5时,物相中除Sb_2O_4、FeSbo_4外,还有FeSb_2O_6生成。随着Fe含量增加,Sb/Fe比高于5时,样品物相为Sb_2O_4和FeSbO_4。在所采用的制备条件下得到的Fe-Sb样品中,观察到有明显的固溶作用。此外,本文还对Fe-Sb氧化物催化剂上甲苯的反应机理进行了讨论。
Samples of mixed oxides of Sb/Fe with different ratios calcined at 500℃ have been investigated by X-ray diffraction, Moessbauer spectroscopy, magnetic susceptibility, infrared spectroscopy, and surface micro-area element analysis. The catalytic activity of the oxidation of toluene to benzaldehyde has also been studied. The results showed that antimony was enriched on the surface of the catalysts. The more the specific enrichment in antimony, the better the selectivity for benzaldehyde. The sample which contains Sb_2O_4 only had the highest selectivity for benzaldehyde. When Sb/Fe=5, Sb_2O_4 and FeSbO_4 occurred in the sample, and an FeSb_2O_6 phase also existed. While the amount of iron was increased in the samples, i. e., when Sb/Fe ratio was higher than 5, the phases of the samples were Sb_2O_4 and FeSbO_4. Solid solubilization was observed with the samples prepared under the conditions adopted. In addition, the mechanism of the toluene oxidation reaction on Fe-Sb oxide catalysts was discussed in detal.
出处
《南京大学学报（自然科学版）》
CAS
CSCD
1990年第3期453-460,共8页
Journal of Nanjing University（Natural Science）
基金
中国科学院科学基金
南京大学校内三项基金资助课题.
