Abstract:
Herein, SiO
2 supported metallic Ni (Ni/SiO
2) and bimetallic Ni-Zn (Ni
xZn/SiO
2) (
x represents the Ni/Zn atomic ratio) catalysts were prepared by the incipient wetness impregnation method and their activities were tested in vapor phase hydrodeoxygenation (HDO) of anisole under 0.1 MPa. The characterization results show that Ni-Zn alloy forms in Ni
xZn/SiO
2 after reduction at 550 °C, and a suitable Ni/Zn atomic ratio (30) leads to smaller alloy particle size and consequently more H
2 adsorption amount than others. In the HDO reaction, the formation of Ni-Zn alloy facilitates the direct deoxygenation pathway and suppresses CO methanation and C−C bond hydrogenolysis, which is ascribed to the isolation effect of the Ni atoms by the oxophilic Zn ones. Ni
30Zn/SiO
2 gives not only higher anisole conversion but also higher selectivity to benzene than Ni/SiO
2. Therefore, the introduction of a suitable amount of oxophilic Zn in Ni/SiO
2 promotes the HDO of anisole to benzene. Finally, we propose that the Ni
30Zn/SiO
2 deactivation is related to the oxidation of Ni-Zn alloy and carbon deposition on the catalyst surface.