Theoretical modeling study of the reaction H + CF4 → HF + CF3. Issue 8 (23rd March 2021)

• Record Type: Journal Article
• Authors: Cobos, Carlos J.; Knight, Gary; Marshall, Paul; Troe, Jürgen
• Is Part Of: International journal of chemical kinetics. Volume 53:Issue 8(2021)
• Page Start: 939
• Page End: 945
• Publication Date: 2021-03-23
• Subjects: Chemical kinetics -- Periodicals; 541.394
• DOI: 10.1002/kin.21492
• Languages: English
• ISSNs: 0538-8066

Abstract

Abstract: The high‐temperature hydrogenation of CF4 in mixtures of CF4 and H2 is assumed to involve the reaction H + CF4 → HF + CF3 . The hydrogen atoms here are either formed by the reaction of F and CF3 (i.e., the products of the thermal dissociation of CF4 ) with H2, or by the thermal dissociation of H2 . In the former case, a complicated chain process is started, while the reaction proceeds in a more direct way in the latter. This article determines the rate constant of the reaction H + CF4 → HF + CF3, characterizing its transition state by quantum‐chemical methods. Over the temperature range 1000–3000 K, the most accurate results for the rate constant can be represented in the form 1.64 × 10 14 ( T /1000 K) 1.95 exp(−178.8 kJ mol –1 / RT ) cm 3 mol –1 s –1, based on coupled cluster theory extrapolated to the complete basis set limit, and incorporating vibrational anharmonicity, electron correlation through CCSDT(Q), and relativistic and non‐Born–Oppenheimer effects.