Study On The Mechanism Of The Activation Of Ethane Via Transition Metal Atom Catalysis

Low-carbon alkane is one kind of saturated carbon-hydrogen compounds which have a large amount in nature but have very low activities. And it is the main material in chemical industry. Because of alkanes'stability, the activation and transformation of them require very harsh conditions. Furthermore, these processes have low selectivities but high product costs. In the industrial production, the technologies of alkanes'activation are mainly making the alkanes transform to petrol-chemical products directly with the help of transition metal catalyzers. To look for the catalyzers with high activation at low temperature, high-selectivities and high stabilities is always the focus in experimental researches. The transition metals play a vital part in the field of ethanes'activiation. The activation of ethane takes up an important place not only in basal researches but also in industries.In this thesis, the microcosmic reaction mechanism of the activation of ethane via transition metal atom M (M=Fe, Co, Ni) catalysis have been studied employing the density functional theory of quantumn chemistry with a simplified model of catalyzer. The aim is to prove up the microcosmic reaction courses and the enery changes in these processes.The conclusions of this thesis are as follows:(1) The microcosmis reaction mechanisms of the actiation of ethane via iron, cobalt and nickel atoms catalysis are divided into two main courses: the activation process of C-C bond and the activation process of C-H bond, they give out methane and hydrogen, respectively.(2) Except for the first step whether to form atom-molecule complex, the activation processes of the three atoms are similar.(3) Analysed from the point of enery, the activation eneries of the rate-determined step of C-C bond activation process of Ni atom and Co atom are higer than the C-H bond activation process, so the activations of C-H bond of Ni atom and Co atom are easier than the C-C bond activation. However, the C-C bond activation of Fe atom is easier than the C-H bond activation.(4) Comparing the reaction courses of the activation process of the three atoms, the rate-determined step of C-C bond activation via iron atom catalysis is lowest, and it of C-H bond activation via nickel atom catalysis is lowest.