Zeolite-Beta-supported platinum catalysts for hydrogenation/hydrodeoxygenation of pyrolysis oil model compounds

Phenol, cresols, guaiacol and eugenol were studied to describe the effect of substituent position and type on the reactivity of these phenolic compounds. Conversion of cresols under deoxygenation/hydrogenation reactivities increased in order m- > o- > p-cresol over Pt/Beta zeolite with Si/Al = 12.7 and o- > m- > p-cresol over the Pt/Beta with lower Al content (Si/Al = 20.7). Major products of cresols hydrogenation were methyl cyclohexanols. Phenol was converted into a mixture of cyclohexane, cyclohexanol and cyclohexanone. An increase in Si/Al ratio of the parent zeolite-based catalysts resulted in a decrease in the overall conversion of cresols and phenol. On the other hand, an increase in Si/Al ratio of catalysts prepared by dealumination led to accelerated conversion of phenol to cyclohexane. Using the lab-prepared mesoporous Beta catalyst with a comparable Si/Al ratio to the commercial one (ca. 20), higher yields of cyclohexanol were obtained in conversion of phenol.

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► Dealuminated zeolite Beta exhibited higher activity in phenol hydrogenation/deoxygenation than its parent form.
► Main product over dealuminated zeolite Beta was cyclohexane while over the parent material cyclohexanol was formed.
► The type and position of substituents in respect to hydroxyl group affected reactivity of phenolic model compounds.