The catalytic cracking of bio-oil is important to produce aromatic hydrocarbons

which can partially replace gasoline or diesel to greatly reduce carbon emissions from transportation. To further promote the formation of aromatic hydrocarbons

this work studied the effects of the preparation method and the acid strength of Ga

2

O

3

/HZSM-5 on catalytic cracking of the bio-oil distilled fraction systematically. The preparation method of Ga

2

O

3

/HZSM-5 had an important effect on its catalytic activity: the Ga

2

O

3

/HZSM-5 prepared by physical mixing showed the low dispersion of active phases and poor pore structure

resulting in its insufficient activity and severe coke deposition; the Ga

2

O

3

/HZSM-5 prepared by precipitation exhibited the higher activity

while many polycyclic aromatic hydrocarbons unfavorable for the subsequent utilization were in the oil phase; the Ga

2

O

3

/HZSM-5 prepared by impregnation showed the highest activity and 35.5% (mass) selectivity of the oil phase

including 80.3% monocyclic aromatic hydrocarbons and 12.0% polycyclic aromatic hydrocarbons. The Brønsted acidity of Ga

2

O

3

/HZSM-5 decreased with Si/Al ratio

leading to the decline in reactant conversion

oil phase selectivity and quality. Meanwhile

the polymerization between monocyclic aromatic hydrocarbons and oxygenates was promoted to produce many polycyclic aromat

ic hydrocarbons and even coke

causing catalyst deactivation.