(CF)CF-C≡N 的大气化学：最有效工业温室气体 SF 的替代品。

Atmospheric Chemistry of (CF)CF-C≡N: A Replacement Compound for the Most Potent Industrial Greenhouse Gas, SF.

机构信息

Department of Chemistry and Biochemistry, California State University , Northridge, California 91330, United States.

Copenhagen Center for Atmospheric Research, Department of Chemistry, University of Copenhagen , 2100 Copenhagen Ø, Denmark.

出版信息

Environ Sci Technol. 2017 Feb 7;51(3):1321-1329. doi: 10.1021/acs.est.6b03758. Epub 2017 Jan 9.

DOI:10.1021/acs.est.6b03758

PMID:27936633

Abstract

FTIR/smog chamber experiments and ab initio quantum calculations were performed to investigate the atmospheric chemistry of (CF)CFCN, a proposed replacement compound for the industrially important sulfur hexafluoride, SF. The present study determined k(Cl + (CF)CFCN) = (2.33 ± 0.87) × 10, k(OH + (CF)CFCN) = (1.45 ± 0.25) × 10, and k(O + (CF)CFCN) ≤ 6 × 10 cm molecule s, respectively, in 700 Torr of N or air diluent at 296 ± 2 K. The main atmospheric sink for (CF)CFCN was determined to be reaction with OH radicals. Quantum chemistry calculations, supported by experimental evidence, shows that the (CF)CFCN + OH reaction proceeds via OH addition to -C(≡N), followed by O addition to -C(OH)═N·, internal H-shift, and OH regeneration. The sole atmospheric degradation products of (CF)CFCN appear to be NO, COF, and CFC(O)F. The atmospheric lifetime of (CF)CFCN is approximately 22 years. The integrated cross section (650-1500 cm) for (CF)CFCN is (2.22 ± 0.11) × 10 cm molecule cm which results in a radiative efficiency of 0.217 W m ppb. The 100-year Global Warming Potential (GWP) for (CF)CFCN was calculated as 1490, a factor of 15 less than that of SF.

摘要

FTIR/烟雾箱实验和从头计算量子化学方法被用于研究（CF）CFCN 的大气化学性质，（CF）CFCN 是一种工业上重要的六氟化硫（SF）的替代化合物。本研究在 700 托的 N 或空气稀释剂中于 296 ± 2 K 下，分别测定了 k（Cl +（CF）CFCN）=（2.33 ± 0.87）×10、k（OH +（CF）CFCN）=（1.45 ± 0.25）×10 和 k（O +（CF）CFCN）≤6×10 cm 分子 s。（CF）CFCN 的主要大气消除途径被确定为与 OH 自由基的反应。量子化学计算得到的结果得到了实验证据的支持，表明（CF）CFCN + OH 反应通过 OH 对-C(≡N)的加成进行，随后是-O 对-C(OH)═N·的加成、内部 H 迁移和 OH 再生。（CF）CFCN 的唯一大气降解产物似乎是 NO、COF 和 CFC(O)F。（CF）CFCN 的大气寿命约为 22 年。（CF）CFCN 的积分截面（650-1500 cm）为（2.22 ± 0.11）×10 cm 分子 cm，导致其辐射效率为 0.217 W m ppb。（CF）CFCN 的 100 年全球变暖潜能值（GWP）为 1490，是 SF 的 1/15。