Study of Ni-ZSM-5 Catalysts in the Hydrogenolysis of Benzyl Phenyl Ether: Effects of Ni Loading, Morphology, and Reaction Conditions

This work investigates the activity of a series of Ni catalysts under a range of reaction conditions for the conversion of a lignin model compound (benzyl phenyl ether) to aromatic compounds. A series of transition metal-based catalysts (Ni-ZSM-5) have been prepared with different metal loadings (5, 10 and 20%) <i>via</i> an excess impregnation method. The materials were characterized using power X-ray diffraction (p-XRD), transmission electron microscopy (TEM) and Brunauer-Emmett-Teller (BET) confirming the formation of a set of dispersed, metallic and spherical nanoparticles on all materials. On a 10% Ni-ZSM-5 material, the formation of a set of nanoparticles with a tetrahedral shape was noted. The materials were applied in the cleavage of the ether bond of a lignin model compound (benzyl phenyl ether) <i>via</i> hydrogenolysis in a range of organic solvents (1-butanol, ethanol, 2-propanol and pentane) and under two different atmospheres (H₂ and Ar). 2-Propanol was shown to be the optimal solvent for the reaction confirming its propensity to act as a H-transfer material and the morphology of the supported nanoparticles was shown to have an important effect on the reactivity of the catalysts.