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之前的工作中已经预测了钛乙烯(C_2H_4Ti)储氢的几何结构,本文将继续利用密度泛函理论(DFT)和B_3LYP杂化密度泛函方法来计算之前预测出的C_2H_4Ti(H_2)_n结构中的C_2H_4Ti和H_2反应的焓变和自由能变.通过焓变和自由能变的计算结果,可以看出:钛乙烯在298 K、250 K、200 K下可以稳定的吸附5个氢分子,同时放出大量的热量,生成的C_2H_4Ti(H_2)_n化合物在常温下也具有热力学稳定性.此外,本文通过Gaussian03中的伯恩近似分子动力学(BOMD)方法计算了C_2H_4Ti(H_2)_5化合物在298 K、250 K、200 K三个温度下的动力学性质.通过动力学研究的结果,可以发现钛乙烯分子在常温298 K下储氢时间不长;同时得到钛乙烯分子在200 K下能长时间稳定吸附五个氢分子,这进一步表明降低温度对钛乙烯分子稳定储氢是有利的.
In the previous work, the geometry of hydrogen storage in titanium ethylene (C 2 H 4 Ti) has been predicted. In this paper, we continue to calculate the previously predicted C_2H_4Ti (H_2) _n structure using density functional theory (DFT) and B_3LYP hybrid density functional theory The enthalpy change and the free energy change of C_2H_4Ti and H_2 reactions can be obtained.The calculated results of enthalpy change and free energy change show that TiOH can stably adsorb 5 hydrogen molecules at 298 K, 250 K and 200 K, A large amount of heat is generated, and the generated C_2H_4Ti (H_2) _n compound also has thermodynamic stability at room temperature. In addition, the calculation of the C_2H_4Ti (H_2) __ compound at 298 K by the method of Bourne approximation molecular dynamics (BOMD) , 250 K and 200 K. The results of kinetic studies show that the hydrogen storage time of titanium ethylene is not long at 298 K at room temperature, Stable adsorption of five hydrogen molecules, which further shows that the lower the temperature of titanium ethylene molecules stable hydrogen storage is beneficial.