Blázquez Sergio, Espinosa Sara, Antiñolo María, Albaladejo José, Jiménez Elena
Departamento de Química Física, Facultad de Ciencias y Tecnologías Químicas, Universidad de Castilla-La Mancha (UCLM), Avda. Camilo José Cela, 1B, 13071 Ciudad Real, Spain.
Instituto de Investigación en Combustión y Contaminación Atmosférica (ICCA), UCLM, Camino de Moledores, s/n, 13071 Ciudad Real, Spain.
Phys Chem Chem Phys. 2022 Jun 15;24(23):14354-14364. doi: 10.1039/d2cp00160h.
Hydrofluoroethers (HFEs), such as CFCHOCH (HFE-263fb2), CHFCFCHOCH (HFE-374pcf), and CFCFCHOCH (HFE-365mcf3), have been proposed in the last few decades as the third-generation replacements for perfluorocarbons (PFCs) and hydrofluorocarbons (HFCs) because of their zero stratospheric ozone depletion potentials and relatively low global warming potentials (GWPs). These GWPs depend on the radiative efficiency (RE) and the atmospheric lifetime () of HFEs due to the reaction with hydroxyl (OH) radicals. The temperature and pressure dependencies of the OH-rate coefficient (()) for HFE-263fb2, HFE-374pcf, and HFE-365mcf3 are not known. Therefore, in this paper, we present the first study on the temperature (263-353 K) and pressure (50-500 torr of helium) dependence of () for the titled HFEs. No pressure dependence of () was observed in the investigated range. From (298 K), estimated are 17 days (for HFE-263fb2), 12 days (for HFE-374pcf), and 13 days (for HFE-365mcf3). The observed -dependencies of () (in cm molecule s) are well described by (3.88 ± 0.89) × 10 exp[-(508 ± 69)/] for HFE-263fb2, (2.81 ± 0.33) × 10 exp[-(312 ± 35)/] for HFE-374pcf, and (2.60 ± 0.31) × 10 exp[-(319 ± 35)/] for HFE-365mcf3. A correlation between log (298 K) and the activation energy () of the process is presented, allowing the prediction of for OH-reactions with other HFEs, exclusively investigated at room temperature. In addition to the kinetic measurements, the infrared absorption cross sections of HFE-263fb2, HFE-374pcf, and HFE-365mcf3 were determined between 520 and 3100 cm. Lifetime corrected REs and GWPs relative to CO at 100 years' time horizon were reexamined. The impact of the investigated HFEs on the radiative forcing of climate change would be negligible.
在过去几十年中，氢氟醚（HFEs），如CFCHOCH（HFE - 263fb2）、CHFCFCHOCH（HFE - 374pcf）和CFCFCHOCH（HFE - 365mcf3），因其平流层臭氧消耗潜能为零且全球变暖潜能值（GWPs）相对较低，被提议作为全氟化碳（PFCs）和氢氟碳化物（HFCs）的第三代替代品。这些全球变暖潜能值取决于氢氟醚与羟基（OH）自由基反应的辐射效率（RE）和大气寿命（）。目前尚不清楚HFE - 263fb2、HFE - 374pcf和HFE - 365mcf3的OH反应速率系数（()）对温度和压力的依赖性。因此，在本文中，我们首次研究了上述氢氟醚的()对温度（263 - 353 K）和压力（50 - 500托氦气）的依赖性。在所研究的范围内未观察到()对压力的依赖性。根据（298 K）估算，（HFE - 263fb2的）为17天，（HFE - 374pcf的）为12天，（HFE - 365mcf3的）为13天。所观察到的()（单位为cm分子s）对的依赖性，对于HFE - 263fb2，可用（3.88 ± 0.89）× 10 exp[-(508 ± 69)/]很好地描述；对于HFE - 374pcf，可用（2.81 ± 0.33）× 10 exp[-(312 ± 35)/]描述；对于HFE - 365mcf3，可用（2.60 ± 0.31）× 10 exp[-(319 ± 35)/]描述。给出了log (298 K)与该过程的活化能（）之间的相关性，这使得能够预测与其他仅在室温下研究过的氢氟醚发生OH反应的。除了动力学测量外，还测定了HFE - 263fb2、HFE - 374pcf和HFE - 365mcf3在520至3100 cm之间的红外吸收截面。重新审视了相对于CO在100年时间跨度下的寿命校正后的REs和GWPs。所研究的氢氟醚对气候变化辐射强迫的影响可忽略不计。
