Research PaperThermal decomposition of HFO-1234yf through ReaxFF molecular dynamics simulation

- The thermal decomposition of HFO-1234yf is investigated using ReaxFF-MD simulation.
- Ten formation pathways of primary products of thermal decomposition are observed.
- The HFO-1234yf molecule decomposed before reacting with oxygen.
- HF, COF2 and CO2 are the main products which agrees with related experiments.

The thermal decomposition of HFO-1234yf with O2 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 CC cleavage, CH cleavage and CF cleavage starts at 2100 K and then release free radicals (CF3, F and H). 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, F, H, HOO and OH) have a great impact on the reaction activity of HFO-1234yf oxidation. The chain transfer process is primarily carried by the conversion from HOO to OH radical. Our work presents the decomposition mechanisms of HFO-1234yf with O2 from the molecule level and provides a reference for the study of the thermal stability of organic working fluids.