La2O3-promoted Ni/H-ZSM-5 catalyzed aqueous-phase guaiacol hydrodeoxygenation to cyclohexanol

Hydrodeoxygenation (HDO) of renewable lignin-derived biomass in aqueous-phase to produce high value-added products is of great significance. However, developing new catalysts with high activity and excellent stability in an aqueous phase faces considerable challenges. Rare earth doping can effectively regulate the water exchange rate constant (WERC) value of the catalyst and play an important role in promoting the hydrolysis of ether bonds. Therefore, in this paper the bimetallic supported catalyst Ni-La 2 O 3 /H-ZSM-5 doped with rare earth metal La 2 O 3 was prepared, and used to catalyze the conversion of the lignin model compound guaiacol to cyclohexanol in the aqueous phase. The conversion of guaiacol catalyzed by 10Ni-3La 2 O 3 /H-ZSM-5 reaches 100%, and the selectivity of the product cyclohexanol is 85%. A series of characterizations illustrate that the doping of La 2 O 3 causes the electron transfer between La 2 O 3 -Ni and changes the distribution of Ni, and a strong metal carrier interaction occurs between the bimetallic Ni-La 2 O 3 and H-ZSM-5. This can effectively promote the hydrolysis of the C–O ether bond in guaiacol and significantly improve the activity of the catalyst. The possible catalytic reaction mechanism of Ni-La 2 O 3 /H-ZSM-5 catalytic conversion of guaiacol was proposed. The results show that the synergistic effect of Ni, La 2 O 3 and H-ZSM-5 is the key to C–O bond cleavage in guaiacol to form cyclohexane. • A Ni/H-ZSM-5 catalyst doped with La 2 O 3 was prepared by the co-precipitation method. • La 2 O 3 caused the electron transfer between La 2 O 3 -Ni and changed distribution of Ni. • La 2 O 3 effectively regulates the interaction between Ni and H-ZSM-5. • La 2 O 3 effectively promotes the hydrolysis of the C-O ether bond in guaiacol.