Facultad de Ciencias y Tecnologías Químicas, Departamento de Química Física, Universidad de Castilla-La Mancha (UCLM), Avda. Camilo José Cela, 1B, 13071, Ciudad Real, Spain.
Instituto de Investigación en Combustión y Contaminación Atmosférica (ICCA), Universidad de Castilla-La Mancha (UCLM), Camino de Moledores, S/N, 13071, Ciudad Real, Spain.
Environ Sci Pollut Res Int. 2024 Aug;31(38):50347-50358. doi: 10.1007/s11356-024-34374-8. Epub 2024 Aug 2.
The kinetic study of the gas-phase reactions of hydroxyl (OH) radicals and chlorine (Cl) atoms with CFCHFCFOCH (HFE-356mec3) and CHFCHFOCF (HFE-236ea1) was performed by the pulsed laser photolysis/laser-induced fluorescence technique and a relative method by using Fourier Transform infrared (FTIR) spectroscopy as detection technique. The temperature dependences of the OH-rate coefficients (k(T) in cms) between 263 and 353 K are well described by the following expressions: 9.93 × 10exp{-(988 ± 35)/T}for HFE-356mec3 and 4.75 × 10exp{-(1285 ± 22)/T} for HFE-236ea1. Under NO-free conditions, the rate coefficients k at 298 K and 1013 mbar (760 Torr) of air were determined to be (2.30 ± 1.08) × 10 cmsand (1.19 ± 0.10) × 10 cms, for HFE-356mec3 and HFE-236ea1, respectively. Additionally, the relative kinetic study of the Cl + CHClCHCl reaction was investigated at 298 K, as it was used as a reference reaction in the kinetic study of the Cl-reaction with HFE-356mec3 and discrepant rate coefficients were found in the literature. The global atmospheric lifetimes were estimated relative to CHCCl at the tropospheric mean temperature (272 K) as 1.4 and 8.6 years for HFE-356mec3 and HFE-236ea1, respectively. These values combined with the radiative efficiencies for HFE-356mec3 and HFE-236ea1 derived from the measured IR absorption cross sections (0.27 and 0.41 W m ppv) yield global warming potentials at a 100-yrs time horizon of 143 and 1473, respectively. The contribution of HFE-356mec3 and HFE-236ea1 to global warming of the atmosphere would be large if they become widespread increasing their atmospheric concentration.
采用脉冲激光光解/激光诱导荧光技术和相对方法，结合傅里叶变换红外（FTIR）光谱作为检测技术，对羟基（OH）自由基和氯（Cl）原子与 CFCHFCFOCH（HFE-356mec3）和 CHFCHFOCF（HFE-236ea1）的气相反应的动力学进行了研究。在 263 至 353 K 之间，OH 速率系数（k(T) 在 cms 中）的温度依赖性很好地由以下表达式描述：对于 HFE-356mec3 为 9.93×10exp{-(988±35)/T}，对于 HFE-236ea1 为 4.75×10exp{-(1285±22)/T}。在无 NO 条件下，在 298 K 和 1013 mbar（760 Torr）下空气的 k 速率系数在 298 K 和 1013 mbar（760 Torr）下分别为（2.30±1.08）×10 cms 和（1.19±0.10）×10 cms，用于 HFE-356mec3 和 HFE-236ea1。此外，在 298 K 下还研究了 Cl+CHClCHCl 反应的相对动力学，因为它在 Cl 与 HFE-356mec3 反应的动力学研究中被用作参考反应，而文献中发现了不一致的速率系数。分别针对 HFE-356mec3 和 HFE-236ea1，在对流层平均温度（272 K）下相对于 CHCCl 估算的全球大气寿命分别为 1.4 和 8.6 年。这些值与从测量的红外吸收截面得出的 HFE-356mec3 和 HFE-236ea1 的辐射效率（0.27 和 0.41 W m ppv）相结合，在 100 年的时间内，全球变暖潜能值分别为 143 和 1473。如果 HFE-356mec3 和 HFE-236ea1 的大气浓度增加，它们对大气变暖的贡献将会很大。
