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-La2O3/H-ZSM-5 doped with rare earth metal La2O3 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-3La2O3/H-ZSM-5 reaches 100%, and the selectivity of the product cyclohexanol is 85%. A series of characterizations illustrate that the doping of La2O3 causes the electron transfer between La2O3-Ni and changes the distribution of Ni, and a strong metal carrier interaction occurs between the bimetallic Ni-La2O3 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-La2O3/H-ZSM-5 catalytic conversion of guaiacol was proposed.(c) 2022 Chinese Society of Rare Earths. Published by Elsevier B.V. All rights reserved.

Automated summary

In this paper, a rare earth metal La2O3-doped bimetallic supported catalyst Ni-La2O3/H-ZSM-5 was prepared and used for the catalytic conversion of lignin model compound guaiacol to cyclohexanol in the aqueous phase. The results showed that the doping of La2O3 changed the distribution of Ni and caused electron transfer between La2O3 and Ni. Additionally, a strong metal carrier interaction occurred between the bimetallic Ni-La2O3 and H-ZSM-5, which effectively promoted the hydrolysis of the C-O ether bond in guaiacol and significantly improved the catalyst's activity.