Facile Decarbonylation Suppresses the <i>Ortho</i> Effect and Ketene Formation in the Catalytic Pyrolysis of Substituted Benzaldehyde Lignin Model Compounds.

ABSTRACT: Ketene intermediates lead to branching and lower phenol selectivities in the catalytic pyrolysis of lignin model compounds, which makes understanding their formation mechanism key to enable targeted process optimization. While gas-phase pyrolysis of methoxy- and hydroxy-substituted benzaldehydes favors fulvenone ketene formation, it is unclear if the same reaction pathways dominate in the presence of Brønsted acid sites. Thus, we tested if HZSM-5 produces fulvenone utilizing operando photoelectron photoion coincidence spectroscopy. Hydroxybenzaldehydes undergo acid-catalyzed decarbonylation, via oxonium mediated hydrogen transfer reactions, to phenol instead of dehydrogenation to fulvenone. The catalytic pyrolysis of anisaldehydes is initiated by demethylation and decarbonylation to

SUBMITTER: Wu X 

PROVIDER: S-EPMC12501935 | biostudies-literature | 2025 Oct

REPOSITORIES: biostudies-literature