H₂O formation during thermal decomposition of isopropanol was measured behind reflected shock waves at temperatures ranging from 1127 to 1621 K at an average pressure of 1.42 atm using a laser absorption technique. Of the five modern chemical kinetics models used to compare the H₂O time histories, the model from Li et al (Combust. Flame 2019;207:171‐185) showed the best overall agreement. Sensitivity and rate of production analyses using the Li et al model (as well as those from AramcoMech 3.0, CRECK, and Togbe et al (Energy Fuel. 2011;25:676‐683)) showed unimolecular dehydration of isopropanol, iC₃H₇OH ⇌ H₂O + C₃H₆ (R1), is nearly the sole reaction controlling H₂O production at early times, allowing for an a priori measurement of the forward rate constant k₁. The Arrhenius expression k₁ (s^–1) = 2.60 × 10¹³ exp(−31 120 K/T) was determined to represent best the data from this study. According to the models and previous experimental investigations, the pressure investigated is well within the high‐pressure limit (HPL) for this reaction. Additional, higher‐pressure experiments also confirmed the HPL assumption. An uncertainty analysis was performed by varying secondary reactions within their uncertainties and examining their effect on the overall prediction, establishing an uncertainty within ±20% for all but the highest temperature cases, which have a maximum uncertainty of ±40%. Experiments conducted with a radical trapper, toluene, showed little influence from radical chemistry, suggesting this estimated uncertainty is fairly conservative. Experimental data from Heyne et al (Z Phys Chem. 2015;229:881‐907) were found to be in good agreement with the rate measurements from this study and, therefore, a second Arrhenius expression, k₁ (s^–1) = 2.11 × 10¹³ exp(−30 820 K/T), was found to represent both datasets well. This second expression has a larger temperature range of 976‐1621 K. The present study provides the first high‐temperature data collected for this reaction, adding to the limited data available for isopropanol in the literature.

中文翻译：

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使用H2O时间历史记录的异丙醇脱水反应速率动力学测量

使用激光吸收技术，在1127至1621 K的温度范围内，平均压力1.42 atm的反射冲击波后面，测量了异丙醇热分解过程中H ₂ O的形成。在用于比较H ₂ O时间历史的五个现代化学动力学模型中，Li等人的模型（Combust.Flame 2019; 207：171-185）显示出最佳的整体一致性。使用Li等人模型（以及来自AramcoMech 3.0，CRECK和Togbe等人（Energy Fuel。2011 ; 25：676-683）的模型）的敏感性和生产率分析显示了异丙醇iC ₃ H _7的单分子脱水OH⇌H ₂ O + C ₃ H ₆（R1）几乎是早期控制H ₂ O产生的唯一反应，因此可以预先测量正向速率常数k ₁。Arrhenius表达式k ₁（s ^–1）= 2.60×10 ¹³  exp（−31 120 K / T）被确定为最能代表这项研究的数据。根据模型和先前的实验研究，所研究的压力完全在该反应的高压极限（HPL）内。另外，高压实验也证实了HPL假设。不确定性分析是通过改变不确定度范围内的二次反应并检查其对总体预测的影响而进行的，对于除最高温度情况外（除最大不确定度为±40％）以外的所有情况，不确定度均在±20％之内。用自由基捕集剂甲苯进行的实验显示，自由基化学几乎没有影响，这表明估计的不确定性相当保守。Heyne等人（Z Phys Chem。2015; 229：881‐907）与该研究的速率测量结果非常吻合，因此，第二个Arrhenius表达式k ₁（s ^–1）= 2.11×10 ¹³ exp（−30 820 K / T）被发现很好地代表了两个数据集。第二个表达式的温度范围更大，为976-1621K。本研究提供了该反应的第一个高温数据，并增加了文献中异丙醇的有限数据。