关键词: 含铁Y沸石, 程序升温还原谱, 酸碱性, 脱氢活性

Abstract: Yzeolites containing Fe(Ⅲ) in framework sites, as the counterions and as the oxide dispersed on zeolite surface were prepared.The reductibility of the zeolite samples was studied by TPRmethod.Below 800℃, the Fe(Ⅲ) cations were reduced to Fe(Ⅲ), the dispersed α-Fe₂O₃ was reduced to low valent iron oxide, but the framework Fe(Ⅲ) ions were unchanged.Unlike pure α-Fe₂O₃, none of the Fe(Ⅲ) species in the zeolite could be reduced to Fe metal.The dehydration and dehydrogenation of isopropanol on the zeolites were used as the probe reactions for measuring the relative acidity and basicity of the samples.It has been verified that the adjustment of the acidity and basicity of zeolites through incorporation of Fe(Ⅲ) ions into the various sites of the zeolite structure is realizable.The dehydrogenation and cracking of ethylbenzene were chosen as the probe reactions to measure the dehydrogenation activity of the different types of Fe(Ⅲ) ions incorporated into the zeolite.Cracking of ethylbenzene can become the major reaction due to the synergism of the metal ions and the strong acid sites on the zeolites.Elimination of the strong acid sites and addition of new basic sites on the zeolite surface through incorporation of Fe(Ⅲ) species can enhance the dehydrogenation selectivity considerably.

Key words: Y zeolite containing Fe(Ⅱ), TPR profile, Acidity and basicity, Dehydrogenation activity