Promoting Effect of Boron on the Stability and Activity of Ni/Mo2C Catalyst for Hydrogenation of Alkali Lignin

Abstract

Different amount of boron-modified Ni/Mo2C were synthesized, characterized and tested during the hydrogenation of alkali lignin, to evaluate the effect of boron on the Ni promoted behavior. xB–Ni/Mo2C (x = 0.5, 1, 3, 5) is found to enhance the lignin conversion and bio-oil yield at the same time, and the highest bio-oil yield was obtained with 1B–Ni/Mo2C (63.8%), under the optimum reaction condition (2 MPa H2, 290 °C and 2 h). Characteristic results of BET method, ICP-OES, XRD, Raman, SEM, TEM, XPS, H2-TPR and NH3/CO2/CO-TPD indicate the improved catalytic performance comes from strong interaction between boron and nickel species, which results in improved surace area, highly dispersed Ni particles, increased acidic sites, thus favors cleavage of the C–O and C–C bonds. A possible reaction mechanism was also present based on the catalytic system.