Experimental and ReaxFF-based molecular dynamics studies of the reaction
of oxygen with DR-2 as a low global warming potential working fluid
Abstract
The cis-1,1,1,4,4,4-hexafluoro-2-butene (DR-2 or HFO-1336mzz(Z)) is a
novel environmentally friendly working fluid with appropriate
physicochemical characteristics. The present work firstly investigates
decomposition mechanism and thermal stability of DR-2 under the
atmosphere containing oxygen (O2) and high temperature experimentally.
The oxidative degradation features of DR-2 were explored at the
temperature of 473-1073 K and the products were monitored by GC-MS and
IC. The experimental and ReaxFF-based molecular dynamics results
demonstrated the promotion effects of O2 on the DR-2 decomposition. The
participation of O2 molecules was supposed to lower the initial thermal
decomposition temperature by 240 K approximately and also would increase
the number of products such as hydrogen fluoride (HF), but the
enhancement effect was weakened by the increasing reaction temperature.
The reasonable Arrhenius parameters calculated from the first-order
kinetic analyses-based reactive molecular dynamics (RMD) simulations.
Combined with density functional theory, the pathways of initial
oxidation decomposition product firstly observed in the experimental and
RMD simulations were proposed in this study. These results may pave the
way for further study of DR-2 as a working fluid with lower global
warming potential.