Liquid phase hydrodeoxygenation of anisole, 4-ethylphenol and benzofuran using Ni, Ru and Pd supported on USY zeolite

The objective of this work is to understand the role of metals on the hydrodeoxygenation (HDO) reaction pathways of three bio-oil model compounds. Ni, Ru and Pd were impregnated on USY zeolite, and the catalysts were characterized to determine metal reduction profile, surface concentration and nanoparticle size. Ru-USY and Pd-USY were completely reduced at a temperature below 450 degrees C, but Ni-USY still contained surface metal oxides after reduction. There was no indication of strong interactions between the metals and USY support. Anisole, 4-ethylphenol and benzofuran were used as bio-oil model compounds, in order to determine the effects of each metal on deoxygenation of methoxy-, phenol and furan functional groups, respectively. Pd-USY was the most effective HDO catalyst, exhibiting the highest turnover frequency for HDO of all three model compounds, in addition to and high selectivity to deoxygenated products. A mechanism was proposed for each model compound, and the kinetics of hydrogenation, dehydration, C-C coupling and ring-opening reactions were determined.