H2-free plastic conversion: converting PET back to BTX via unlocking hidden hydrogen.

Under the strong desire of seeking circular economy, making fuels and chemicals via plastic degradation become important research topics in the 21st century. Here, we realized the first example of the H2 -free PET conversion to BTX via unlocking hidden hydrogen in ethylene glycol part over Ru/Nb2O 5 catalyst. Among the whole process (hydrolysis, reforming and hydrogenolysis/decarboxylation), the parallel hydrogenolysis and decarboxylation are competitive and the rate-determining step. Ru/Nb2O5 exhibited superior hydrogenolysis and poorer decarboxylation performance in direct comparison with Ru/NiAl2O4 , accordingly contributing to the distinct selectivity to alkyl aromatics among BTX. Ru species on Nb2O5 , unlike those on NiAl2O4 , showed more Ruδ+ species owning to the strong interaction between Ru and Nb2O5 , restricting the undesired decarboxylation. Along with NbO x species for the C-O bonds activation, splendid reactivity towards the H2 -free conversion of PET back to BTX with alkyl aromatics being dominant is achieved. This H2 -free system is also capable of handling common real PET plastics back to BTX, adding new options in the circular economy of PET.