Production of Phenol and Cresol from Guaiacol on Nickel Phosphide Catalysts Supported on Acidic Supports

Partial hydrodeoxygenation (HDO) of bio-oil derived from the pyrolysis of lignin can yield higher value added products, such as phenol derivatives. The HDO of 2-methoxyphenol (guaiacol) was studied over nickel phosphide (Ni2P) supported on various acidic substrates. The substrates were the microporous zeolite ZSM-5, a fluidized catalytic cracking (FCC) support consisting of USY zeolite embedded in a silica-alumina matrix, and an amorphous silica-alumina (ASA) material. Guaiacol was used as reactant because it is a good model compound for species derived from the lignin portion of biomass. The order of activity was Ni2P/ASA > Ni2P/FCC > Ni2P/ZSM-5. Contact time measurements indicated that the main pathway on Ni2P/ASA, the most active catalyst, was conversion of guaiacol to the primary intermediate catechol, which was then dehydroxylated to phenol.