Hydrogenolysis of saturated hydrocarbons: II. Comparative hydrogenolysis of some aliphatic light hydrocarbons on platinum-alumina
Hydrogenolysis of saturated hydrocarbons: II. Comparative hydrogenolysis of some aliphatic light hydrocarbons on platinum-alumina
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饱和烃的氢解：II。
DOI：
10.1016/0021-9517(76)90375-4
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发表时间：
1976
影响因子：
7.3
通讯作者：
R. Maurel
中科院分区：
文献类型：
--
作者：
G. Leclercq;L. Leclercq;R. Maurel
在常压流动反应器中研究了乙烷、丙烷、丁烷、异丁烷、新戊烷和异戊烷在PtAl2O3上催化氢解的动力学。这些碳氢化合物按照 300 °C 下氢解速率增加的顺序排列：乙烷、丙烷、新戊烷、异丁烷、丁烷和异戊烷。确定了不同类型CC键断裂的动力学级数和表观活化能。烃分压的指数始终为正，而氢气压力的指数可以为正或负，并且在某些情况下，对于特定的氢气压力，该速率是最大的。所有这些观察结果都与 Cimino、Boudart 和 Taylor 提出的动力学方案一致 [J.物理。化学 58, 596 (1954)]。根据这些假设，所有研究的碳氢化合物都发现了广泛脱氢的表面物质。碳-碳键断裂的速率常数随烃类变化不大。另一方面，吸附平衡受烃类结构的影响很大：在同系中，吸附平衡常数随着分子量的增加而增大，但对于相同碳原子数，当支化增加时，吸附平衡常数减小。
Kinetics of catalytic hydrogenolysis of ethane, propane, butane, isobutane, neopentane and isopentane on PtAl2O3have been investigated in a flow reactor at atmospheric pressure. These hydrocarbons are arranged according to increased rates of hydrogenolysis at 300 °C in the series: ethane, propane, neopentane, isobutane, butane and isopentane. The kinetic orders and apparent activation energies of the breaking of different types of CC bonds have been determined. The exponents of hydrocarbon partial pressure are always positive, while the exponent of hydrogen pressure can be positive or negative, and in some cases the rate is maximum for a certain hydrogen pressure. All these observations are consistent with the kinetic scheme proposed by Cimino, Boudart and Taylor [J. Phys. Chem.58, 596 (1954)]. In terms of these hypotheses an extensively dehydrogenated surface species has been found for all hydrocarbons investigated. The rate constant of the rupture of the carbon-carbon bond is not much changed with the hydrocarbon. On the other hand, the adsorption equilibrium is greatly influenced by the structure of the hydrocarbons: the adsorption equilibrium constant increases with the molecular weight in a homologous series, but for an equal number of carbon atoms, it decreases when branching increases.