There is significant emphasis on the destruction of HFC refrigerants in China

culminating in an urgent need to explore efficient and mild HFC refrigerant degradation methods. In this study

a typical HFC refrigerant

HFC-134a

was chosen as the object of combined experimental studies and quantum chemical calculations

and the degradation rate was considered the main criterion for exploring the high-level pathway of refrigerant degradation. In terms of quantum chemistry

the reaction paths of HFC-134a under pyrolysis and oxidative decomposition conditions were explored. Under both paths

detectable stable products such as CHF=CF2 and HF were easily produced. During pyrolysis

the first step in the chemical bond cleavage is the rate-determining step. Compared to the pyrolysis path

the oxidative decomposition path has a lower reaction energy barrier

which is conducive to the rapid occurrence of the reaction. Experimental results showed that the degradation rate of HFC-134a increased from 11% to 66% with the increase in temperature in the range of 240–360 ℃. By fitting the kinetic constant of the reaction

the pre-exponential factor (A) of HFC-134a was determined as 7471.04 s-1

and the activation energy (Ea) was 54.16 kJ/mol

which were consistent with the simulated chemical reaction energy barrier.