Catalytic pyrolysis mechanism of lignin moieties driven by aldehyde, hydroxyl, methoxy, and allyl functionalization: the role of reactive quinone methide and ketene intermediates.

ABSTRACT: The catalytic pyrolysis of guaiacol-based lignin monomers, vanillin, syringol, and eugenol over commercial HZSM-5 has been investigated using operando Photoelectron Photoion Coincidence (PEPICO) spectroscopy to unveil the reaction mechanism by detecting reactive intermediates, such as quinone methides and ketenes, and products. Vanillin shares the decomposition mechanism with guaiacol due to prompt and efficient decarbonylation, which allows us to control this reaction leading to a phenol selectivity increase by switching to a faujasite catalyst and decreasing the Si/Al ratio. Syringol first demethylates to 3-methoxycatechol, which mainly dehydroxylates to o- and m-guaiacol. Ketene formation channels over HZSM-5 are less important here than for guaiacol o

SUBMITTER: Pan Z 

PROVIDER: S-EPMC11363027 | biostudies-literature | 2024 Sep

REPOSITORIES: biostudies-literature