【摘要】 对氧化态和硫化态的Fe-Mo/Al₂O₃加氢脱硫催化剂进行了Mossbauer谱学的研究。催化剂样品主要含有Fe₂（MoO₄）₃和α-FeOOH。负载于γ-AlOOH后,Mossbauer谱产生明显变化。硫化后,得到Fe_1-xS的磁分裂谱,并在中间部分叠加了一个δ=0.35mm/s,△=0.78mm/s的双峰。由于这组双峰的出现是以Mo的存在为条件,并伴随着噻吩加氢脱硫明显的催化活性的出现,故说明存在着（Fe-Mo-S）活性相。更多还原

【Abstract】 Fe-Mo/Al2O3 catalyst prepared by coprecipitation method is examined for hydrodesulfurization(HDS) of organic sulfur compounds. The results obtained by the magnetic and Mossbauer spectroscopic methods reveal that the paramagnetic iron molybdate and the superparamagnetic a-FeOOH are the principal components originated from iron in this catalyst sample. In this paper, the fresh and the sulfided catalyst samples are characterized by the Mossbauer spectroscopy.For the fresh δFe-Mo/Al2O3 catalysts of various atomic ratios of Fe/Mo, the Mossbauer spectra display an overlapped spectra of at least two sets of double lines, one of which with Fe=0.40mm/s and △= 0.20 mm/s and another with Fe=G.35mm/s and △= 0.82mm/s. The former is due to the presence of δFe2(MoO4)3 and the latter of a-FeOOH. For the sulfided catalyst samples, the multiple six lines spectra of Fe1-xS are overlapped of another double line with Fe=0.35mm/s and △=0.78 mm/s in the middle part of the Mossbauer spectrum. In virtue of this double line appeared only if Mo presented in the catalyst sample and accompanied with appreciable HDS catalytic activity for thiophene, it is reasonable to conclude that a phase composed of Fe, Mo, and S behaves as the active phase, i. e. (Fe-Mo-S) phase. Since the atomic ratio of Mo/Fe for most samples is much lower than that for Fe2(MoO4)3, it is assumed that nearly the whole amount of Mo is in the (Fe-Mo-S) phase and the evaluated values for (Fe/Mo)a inside the active phase are not constant.The relationship between the catalytic activity of HDS of Fe-Mo/ A12O3 catalyst and the atomic ratio of Fe/Mo as well as the support content is discussed on the basis of the experimental results. A probable model for the active (Fe-Mo-S) phase is proposed.更多还原