Stereodynamics Study of the Reaction of O(3P) with CH4 (v = 0 ,j = 0)

Yufang Liu,Yali Gao,Hongsheng Zhai,Jinfeng Sun,Deheng Shi

doi:10.3390/ijms10052146

Abstract

A new London-Eyring-Polanyi-Sato (LEPS) potential energy surface (PES) is used in the O + CH4 → OH + CH3 reaction via the quasiclassical trajectory method (QCT). Comparing with the experiments and the former ab initio calculations, the new LEPS PES describes the actual potential energy surface of the O + CH4 reaction successfully. The four polarization dependent “generalized” differential cross sections (PDDCS) are presented in the center of mass frame. In the meantime, the distribution of dihedral angle [P(φr), the distribution of angle between k and j′ (P(θr)] and the angular distribution of product rotational vectors in the form of polar plots in θr and φr (P(θr, φr) are calculated. The isotope effect for the reactions O + CD4 is also calculated. These results are in good agreement with the experiments.

Highlights

The reactions of ground-state atomic oxygen, O(3P), with hydrocarbons are the important initial steps of oxidation in combustion processes [1] and in Low Earth Orbit (LEO) conditions [2]
A new LEPS potential energy surface (PES) with a different set of Sato parameters has been calculated in our work
The full three-dimensional angular distribution associated with k, k and j can be represented by a set of generalized polarization-dependent differential cross-sections (PDDCSs) in the CM frame

Summary

Introduction

The reactions of ground-state atomic oxygen, O(3P), with hydrocarbons are the important initial steps of oxidation in combustion processes [1] and in Low Earth Orbit (LEO) conditions [2] Among those reactions, the abstraction reaction O(3P) + CH4 → OH + CH3 has attracted considerable interest, both in experimental [3,4,5,6,7,11] and theoretical [8,9,10,12,13,14,15,16,17,18,19,20] calculations over the past decades. There is only one experimental work [27] relate to the product angular distribution (k - k′), scalar and two-vector properties of the reaction were analyzed using the QCT method [14], the full-dimensional trajectory [13,20] calculations only relate to the k - k′. We calculated the product rotational polarization, the scattering-angle resolved product rotational alignment, the vector correlations of the reaction O(3P) + CH4 → OH + CH3 and the isotope effect for the reactions O + CH4/O + CD4

Results and Discussion

Experimental Section

Potential energy surface

Conclusions