Thermal decomposition of HFO-1234yf through ReaxFF molecular dynamics simulation

摘要

The thermal decomposition of HFO-1234yf with O-2 was studied by ReaxFF molecular dynamics simulation at the wide temperature ranges of 1900-3500 K. The results show that the initial reactions of HFO-1234yf pyrolysis including C-C cleavage, C-H cleavage and C-F cleavage starts at 2100 K and then release free radicals ((CF3)-C-center dot, F-center dot and H-center dot). The oxidation reaction starts at 2500 K and numerous intermediates (H2O, CF3OH and FCOOH) are produced. The main products observed from simulation are HF, COF2 and CO2 and these products agree with the result of related experiments. Ten formation pathways of primary products are observed from ReaxFF. The concentrations of free radicals (FCOO center dot, F-center dot, H-center dot, HOO center dot and (OH)-O-center dot) have a great impact on the reaction activity of HFO-1234yf oxidation. The chain transfer process is primarily carried by the conversion from HOO center dot to center dot OH radical. Our work presents the decomposition mechanisms of HFO-1234yf with O-2 from the molecule level and provides a reference for the study of the thermal stability of organic working fluids. (C) 2017 Elsevier Ltd. All rights reserved.