Mechanism of thermal decomposition of HFO-1234yf by DFT study

Twenty-two chemical reaction pathways of thermal decomposition of 2,3,3,3-tetrafluoro-1-propene (HFO-1234yf, CF₃CFCH₂) are proposed to investigate the formation mechanism of some possible products (CF₃H, CF₄, HF, H₂) by using density function theory (DFT) simulations with M06-2X/6–311++(d,p) level of theory. The results point out that the ground state CF₃CFCH₂ will excite into the lowest triplet state CF₃CF-CH₂ favorably in the first step with an energy barrier of 264.67 kJ mol^?1 and pathway 5 is the most preferred route of homolytic cleavage reactions with the lowest energy barrier of 205.70 kJ mol^-1. F radical is hard to generate during thermal decomposition processes because of its higher energy barrier. H radical and CF₃ radical play a dominant role in thermal decomposition of HFO-1234yf. H-abstraction and F-abstraction reactions are proposed in subsequent radical attacking chain reactions. CF₃H and H₂ are easier to be generated due to their lower energy barriers. Our work presents the mechanism of thermal decomposition of HFO-1234yf from the molecule level and provides a reference for studying the thermal stability of other working fluids.