As potential alternatives to HFC-134a, the hydrofluoroolefin (HFO) mixture, HFO-1234yf/HFO-1216, offers a low global warming potential (GWP) and reduced or nonflammability. This makes it suitable for use in heat pumps and organic Rankine cycle (ORC) systems. Thermal stability is a critical criterion for screening working fluids in heat pumps and ORC systems. This study investigates the thermal stability of HFO-1234yf/HFO-1216 through a combination of experimental and theoretical approaches. Experimental results indicate that HFO-1234yf/HFO-1216 undergoes decomposition within the temperature range of 170 to 210 °C. The amount of these pyrolysis products was found to increase with rising temperature. At 210 °C, the primary pyrolysis products identified were HF, CHF3, C2F4, C3HF5, and C6F12. Furthermore, the formation mechanisms and pathways of these pyrolysis products have been investigated by using density functional theory (DFT) and ReaxFF reactive molecular dynamics simulations. Among the reactive intermediates, the CF3 radical was identified as the predominant species readily generated upon thermal activation of both HFO-1234yf and HFO-1216.
Ouyang et al. (Wed,) studied this question.