Figure 5.

¹H (left) and ¹³C (right) MAS NMR spectra of 100 μl glycerol in 75 psig O₂ heated to various temperatures prior to cooling to monitor the thermal degradation processes taking place. ¹H: the spectrum at 133 °C completed after 1 h of heating, 175 °C completed after 3 h of heating at 175 °C. ¹³C: the spectrum at 133 °C completed after 46 h of heating, 175 °C completed after 29 h of heating at 175 °C. The total heating time including temperature ramping was ~ 77 h.