Influence of Zeolite Composition and Structure on Hydrogen Transfer Reactions from Hydrocarbons and from Hydrogen
Influence of Zeolite Composition and Structure on Hydrogen Transfer Reactions from Hydrocarbons and from Hydrogen
复制标题
DOI：
10.1006/jcat.1996.0097
复制
发表时间：
1996-04
影响因子：
7.3
通讯作者：
J. Meusinger;A. Corma
中科院分区：
文献类型：
--
作者：
J. Meusinger;A. Corma
在623K、2.5MPa的反应压力下，正庚烷的裂解优先进行双分子裂解。这对于具有不同密度的酸位点的MFI型和FAU型沸石得到证实。发现MFI型沸石的活性与布朗斯台德酸中心的数量呈线性关系。在FAU型沸石的情况下，观察到每个布朗斯台德酸位点的活性随着酸位点浓度的增加而降低。这是由酸强度的差异解释的。所有研究的酸性沸石样品都能够在实际反应条件下活化氢。在正庚烷裂解过程中，活性氢参与了双分子氢转移反应。本文根据氢对裂化过程中速率控制步骤的影响讨论了氢的作用，并通过正庚烷在FAU型样品上的裂化动力学研究证实了氢的作用。从氢以及从烃的氢转移以相同的方式受到沸石结构和酸位密度的影响。
Abstract The cracking ofn-heptane proceeds at 623 K and a reaction pressure of 2.5 MPa preferentially according to the bimolecular cracking route. This was confirmed for MFI- and FAU-type zeolites with varying density of acid sites. The activity was found to be linearly dependent on the number of Bronsted acid sites for MFI- type zeolites. In the case of FAU-type zeolites it was observed that the activity per Bronsted acid site decreases with increasing concentration of acid sites. This was explained by differences in acid strength. All the investigated acid zeolite samples were able to activate hydrogen under the actual reaction conditions. The activated hydrogen was found to participate in bimolecular hydrogen transfer reactions duringn-heptane cracking. The action of hydrogen is discussed on the basis of its influence on the rate-determining step during cracking and was confirmed by a kinetic study ofn-heptane cracking on a FAU-type sample. Hydrogen transfer from hydrogen as well as from hydrocarbons was influenced in the same way by zeolite structure and acid site density.