Promotional effect of F for Pd/HZSM-5 catalyst on selective HDO of biobased ketones

In this work, fluorine-enhanced Pd/HZSM-5 catalyst was synthesized for selective hydrodeoxygenation of biomass derived ketones by using polymethylhydrosiloxane (PMHS) as the hydrogen source under mild conditions. According to characterizations, the highly electronegative F can replace the OH group on the HZSM-5 to form a special F-Al structure over the Pd/HZSM-5 catalyst, thereby the surface morphology, hydrophobicity, acidity and electronic character of Pd/HZSM-5 catalyst can be regulated by the amount of fluorine doping. The Pd-F/HZSM-5(5) catalyst with F-doping at 5 wt% exhibited the best catalytic activity and water-resistance for acetophenone hydrodeoxygenation among a series of Pd-based catalysts, achieving >99% yield and 93.7% yield toward ethylbenzene at 65 degrees C for 3 h in ethanol and in 95 vt% ethanol, respectively. The F-Al structure formed by the F modification replaces the -OH on the HZSM5, which inhibited the adsorption to water on the metal active site of the catalyst, thus effectively improving the catalytic performance for selective hydrodeoxygenation of biomass-derived ketones. In addition, the as-prepared Pd-F/ HZSM-5(5) catalyst with an excellent circulation capability after 5 times use, and the >90% yield of deoxidation production can be obtained for the HDO of various biomass-derived ketones. (C) 2021 Elsevier Ltd. All rights reserved.

Automated summary

Fluorine-enhanced Pd/HZSM-5 catalyst was synthesized for selective hydrodeoxygenation of biomass derived ketones using PMHS as hydrogen source. The catalyst exhibited excellent catalytic performance and circulation capability for the reaction, achieving high yields of deoxidation production.