土卫六大气中H2和N+反应的动力学研究

依据Titan大气的压强和温度条件计算了N++H2→NH++H反应的热化学函数. 结果发现, 该反应是一个吸热反应, 在Titan的低温环境中不具有反应自发性. 运用量子化学理论计算研究了反应的动力学性质, 发现该反应在300 K温度下的反应速率k=4.16×10−10 cm3•mol−1•s−1, 在实验室温度下(298.15 K)的反应势垒是109.847 kJ•mol−1. 依据Titan电离层气压温度条件计算了90 Pa压强条件下1 K到5000 K温度范围内(极低温度和极高温度)的 反应活化能和反应速率, 研究发现低温下该反应的反应速率非常低, 而且, 随着温度的降低, 反应速率急剧降低. 理论计算值和文献中的实验值也符合得较好, 理论计算数据可以为星际分子的模拟实验提供一定的参考.

Reaction of H2 and N+ Ion under Titan's Atmosphere

The thermochemical properties of reaction N++H2→NH++H have been computed under Titan's atmosphere conditions. It is observed that this reaction is an endothermic reaction and cannot proceed forward spontaneously under low temperature.The rate for this reaction at 300K has been calculated as k=4.16×10-10 cm3·mol-1·s-1.The reaction barrier is 109.847 kJ·mol-1 at 298.15 K,which is probable too high to allow this reactio to occur in the atmosphere of Titan. The kinetic properties of the reaction are calculated at a pressure of 90 Pa and a temperature ranging from 1 to 5000 K. It is found that this reaction has very low reaction rate under low temperature in Titan's atmosphere and that the rate decreases drastically with decreasing temperature. This result should be applicable to interstellar place of the low temperature values. The results are compared with those obtained from experiments.