Density functional theory studies on combustion oxidative decomposition mechanism of 3,3,3-trifluoropropene

The environmentally friendly refrigerant 3,3,3-trifluoropropene (HFO-1243zf) suitable for refrigeration and heat pump systems has flammability. Based on density functional theory, the oxidation decomposition mechanism of 3,3,3-trifluoropropene was studied, including the main initial oxidation decomposition and subsequent reactions. The results indicate that among the initial thermal decomposition reactions, the reaction with the lowest energy barrier is simultaneous elimination of HF, followed by CC bond breaking to form center dot CF3. In the H abstraction reaction, the reaction energy barrier of H atom capture by center dot F is the lowest. In F abstraction reaction, the center dot H is the most active. In the addition reaction, the reaction energy barrier of center dot F is the lowest. The energy barriers of reactions involving different free radicals, from high to low, are: thermal decomposition, F abstraction, H abstraction and addition reaction. The subsequent reactions mainly involve the generation pathways of center dot CF3 and the formation of stable products.