【摘要】 采用量子化学中的从头计算法 ,研究了金属镍对催化裂化催化剂的污染特性 ,建立了镍与烃分子发生脱氢反应的量子化学计算模型 ,确定了反应的速控步骤 ,并着重研究了镍价态变化 (Ni0 ,Ni+,Ni2 +)对烃分子脱氢反应活性的影响规律。通过计算得出Ni0 ,Ni+,Ni2 +在脱氢反应速控步骤的活化能分别为 2 15 .0 85kJ/mol,32 0 .0 0 5kJ/mol和 6 5 0 .5 0 2kJ/mol,显示出低价镍脱氢活性强的特点。这与标准轻油微反活性评价实验结果相吻合更多还原

【Abstract】 The effect of nickel deposits on the properties of FCC equilibrium catalysts was studied using the standard microactivity test of light oil and quantum chemical method of ab intio calculations. A simplified dehydrogenation reaction model is established and used to investigate the difference in the dehydrogenation activity of the nickels with different valency (Ni 0,Ni +,Ni 2+ ). The activation energies of the low spin potential energy surface (PES) for Ni\+0, Ni + and Ni 2+ in the rate controlling step of dehydrogenation reaction are calculated. The corresponding values are 215.085 kJ/mol, 320.005 kJ/mol and 650.502 kJ/mol respectively. The results show that the order of dehydrogenation activities is Ni\+0, Ni\++, Ni\+\{2+\}. The calculated results from the model are in good accordance with the standard microactivity test results.更多还原