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在前文的基础上,根据红外吸收光谱,场离子质谱,俄歇电子能谱,低能电子衍射,吸附后金属输出功增量,~(15)N_2-~(14)N_2同位素交换,D_2对氨合成反应速率的反同位素效应,氢对氮吸附量、吸附速度、氨生成速度的影响,同位素方法测出的化学计量比等方面的实验事实,以及量子化学计算结果,提出在铁催化剂上氨合成的催化作用机理,并推导出相应的动力学方程式。这方程形式上与1963年推广式一致,但动力学机理与微观参数物理化学意义不同。本文不主张气相H_2分子与吸附氮作用而主张吸附的N_2δ~-与诱生吸附的H~δ~+(或H_2δ~+)相作用,为速率控制步骤之一,从而较好地解释氮解离的化学推动力。同时,说明了N_2与H_2不互相竞争吸附位的微观原理。综合评论了国际上主要的氨合成动力学方程式及其互相间的联系。 根据本文推得的动力学方程,将0zaki-Taylor实验数据重新处理,结果表明本文方程与实验值符合程度更好。例如,由该方程处理实验数据求得的动力学参数a与压力的关系,αH/αD随温度变化的关系,都与理论估计符合。本文还求得某些新的动力学参数,并讨论其物化涵义。结果表明,D_2对氨合成反应速率的反同位素效应是热力学因素(K_(ND_3)>K_(NH_3),K_(D_2)>K_(H2))以及动力学因素[(k_2)_D>(k_2)_H]的加和,而不是Ozaki所提出的
On the basis of the above, according to the infrared absorption spectroscopy, field ion mass spectrometry, Auger electron spectroscopy, low energy electron diffraction, the incremental output of metal after adsorption, isotope exchange of ~ (15) N_2- ~ (14) N_2, The anti-isotope effect of synthetic reaction rate, the effect of hydrogen on the amount of adsorbed nitrogen, the adsorption rate and the ammonia formation rate, the stoichiometric ratio measured by isotope method and the quantum chemical calculation results, The catalytic mechanism, and derived the corresponding kinetic equation. This equation is formally consistent with that of 1963, but its kinetic mechanism and micro-parameters have different meanings. This paper does not advocate that the role of vapor phase H 2 molecule adsorbed nitrogen and adsorption of N 2 δ ~ - and induced adsorption of H ~ δ ~ + (or H_2δ ~ +) phase, rate control one of the steps to better explain the nitrogen solution Chemical driving force. At the same time, the microscopic principle of N 2 and H 2 that do not compete with each other is described. A comprehensive review of the major international ammonia synthesis kinetic equations and their relations with each other. According to the kinetic equation deduced in this paper, the experimental data of 0zaki-Taylor are reprocessed. The results show that the equation in this paper is in good agreement with the experimental data. For example, the relationship between the kinetic parameters a and the pressure obtained from the experimental data processing and the relationship between αH / αD and temperature is consistent with the theoretical estimation. In this paper, some new kinetic parameters are also obtained, and their connotations are discussed. The results showed that the antiisotopic effect of D_2 on the reaction rate of ammonia synthesis was determined by the thermodynamic factors (K_ (ND_3)> K_ (NH_3), K_ (D_2)> K_ (H2) _H], not Ozaki’s