We have used the single‐pulse shock tube technique with postshock GC/MS product analysis to investigate the mechanism and kinetics of the unimolecular decomposition of isopropanol, a potential biofuel, and of its reaction with H atoms at 918‐1212 K and 183‐484 kPa. Experiments employed dilute mixtures in argon of isopropanol, a radical scavenger, and, for H‐atom studies, two different thermal precursors of H. Without an added H source, isopropanol decomposes in our studies predominantly by molecular dehydration. Added H atoms significantly augment decomposition, mainly by abstraction of the tertiary and primary hydrogens, reactions that, respectively, lead to acetone and propene as stable organic products. Traces of acetaldehyde were observed in some experiments above ≈ 1100 K and establish branching limits for minor decomposition pathways. To quantitatively account for secondary chemistry and optimize rate constants of interest, we employed the method of uncertainty minimization using polynomial chaos expansions (MUM‐PCE) to carry out a unified analysis of all datasets using a chemical model–based originally on JetSurF 2.0. We find: k(isopropanol → propene + H₂O) = 10^{(13.87 ± 0.69)} exp(−(33 099 ± 979) K/ T) s⁻¹ at 979‐1212 K and 286‐484 kPa, with a factor of two uncertainty (2σ), including systematic errors. For H atom reactions, optimization yields: k(H + isopropanol → H₂ + p‐C₃H₆OH) = 10^{(6.25 ± 0.42)} T^2.54 exp(−(3993 ± 1028) K /T) cm³ mol⁻¹ s⁻¹ and k(H + isopropanol → H₂ + t‐C₃H₆OH) = 10^{(5.83 ± 0.37)} T^2.40 exp(−(1507 ± 957) K /T) cm³ mol⁻¹ s⁻¹ at 918‐1142 K and 183‐323 kPa. We compare our measured rate constants with estimates used in current combustion models and discuss how hydrocarbon functionalization with an OH group affects H abstraction rates.

中文翻译：

---

冲击管实验中的异丙醇分解和与H原子反应的动力学以及使用多项式混沌展开的不确定性最小化方法（MUM-PCE）进行速率常数优化

我们将单脉冲激波管技术与震后GC / MS产品分析一起使用，研究了潜在分子生物燃料异丙醇的单分子分解及其在918-1212 K和183-484处与H原子反应的机理和动力学。千帕 实验中使用了稀疏的异丙醇氩气混合物（自由基清除剂），并且在H原子研究中使用了H的两种不同的热前体。在没有添加H源的情况下，异丙醇在我们的研究中主要通过分子脱水而分解。添加的H原子主要通过提取叔氢和伯氢来显着增强分解，反应分别导致生成稳定的有机产物丙酮和丙烯。在约1100 K以上的某些实验中观察到乙醛的痕迹，并为次要的分解途径建立了分支极限。为了定量说明次生化学并优化目标速率常数，我们采用了基于多项式混沌展开式（MUM-PCE）的不确定性最小化方法，使用化学模型对所有数据集进行了统一分析（最初基于JetSurF 2.0）。我们发现：k（异丙醇→丙烯+ H ₂ O）= 10 ^{（13.87±0.69）} exp（-（33 099±979）K / T）s ^-1在979-1212 K和286-484 kPa时，存在两个不确定因素（2σ），包括系统误差。为氢原子的反应，产率优化：ķ（H +异丙醇→H ₂ + p -C ₃ ħ ₆ OH） = 10 ^{（6.25±0.42）} Ť ^2.54 EXP（ - （3993±1028）K / Ť）厘米³摩尔^{- 1} s ^-1和k（H +异丙醇→H ₂ + t ‐C₃ H ₆ OH） = 10 ^{（5.83±0.37）} T ^2.40 exp（-（1507±957）K / T）cm ³ mol ^-1 s ^-1在918-1142 K和183-323 kPa下。我们将测得的速率常数与当前燃烧模型中使用的估计值进行比较，并讨论带有OH基团的烃官能化如何影响H提取速率。