Boric acid modified MOF-derived Ni@C/Al2O3-xB catalysts boosting the hydrodeoxygenation of guaiacol and raw bio-oil

Abstract

Catalytic hydrodeoxygenation (HDO) of lignin-derived phenolic compounds into valuable hydrocarbons is of great significance but remains a challenge. Herein, a series of B modified Ni@C/Al₂O₃-B catalysts were prepared via one-pot solvothermal method followed by direct pyrolysis of Ni-MOF-74/Al₂O₃-B under N₂ atmosphere. The effect of dopant B on structure and acidity of the prepared catalysts were studied by multitechniques. It is found the increase in B content increased the specific area and strengthened the acidity of the catalysts, thus contributing to the improved HDO activity. Ni@C/Al₂O₃-3B catalyst with a B content of 3 mmol exhibited the best HDO activity, guaiacol was completely converted with 91.7 % cyclohexane selectivity at 275 ℃, 3 MPa, 2 h. And anisole was completely converted with 94.5 % cyclohexane selectivity at 275 ℃, 2 MPa, 1 h. Ni@C/Al₂O₃-3B catalyst also catalyst displayed excellent HDO performance for real bio-oil. This work can provide technical guidance for designing highly active non-precious catalysts applied in HDO process of lignin into green fuel and value-added chemicals.