Catalytic Upgrading of Bio-Oil over Cu/MCM-41 and Cu/KIT-6 Prepared by β-Cyclodextrin-Assisted Coimpregnation Method

Cu loaded MCM-41 and KIT-6 are prepared by beta-cyclodextrin (CD) assisted coimpregnation method (Cu/MCM-41-CD and Cu/KIT-6-CD) for in situ catalytic upgrading of bio-oil derived from the fast pyrolysis of biomass. It is found that Cu/MCM-41-CD and Cu/KIT-6-CD exhibit higher catalytic activity for promoting the deoxygenation from the bio-oil when compared with those prepared by conventional impregnation method. 20 wt % of Cu loaded MCM-41-CD and KIT-6-CD shows the highest catalytic activity, by which the upgraded bio-oil is rich in monocyclic aromatic hydrocarbons such as benzene, toluene, and xylene with the total relative maximum hydrocarbon amounts of 73.2% and 86.1%. After reuse of the regenerated catalyst for four cycles, no serious reduction of total relative hydrocarbon amount is found. The possible upgrading mechanism is proposed. It is expected to provide a new direction with a green method for development of the catalyst for the upgrading of bio-oil.