Abstract:

The graphene oxide(GO) dispersion was prepared by the modified Hummer's method using flake graphite as raw material. The amorphous Ni-P/rGO composite catalyst was prepared by chemical reduction method, and the rosin hydrogenation was used as the probe reaction to study the effects of catalyst preparation conditions on the catalytic performance. And the process conditions of rosin hydrogenation were further optimized by orthogonal test. The results showed that the optimum preparation conditions were the mass ratio of Ni element to GO 6:1, the pH value of the solution 11, the ratio of n(P)/n(Ni) 5:1, the temperature 70℃, and the reaction time 4.5 h. The catalyst had a high activity for hydrogenation of rosin under the suitable hydrogenation conditions of 5% catalyst, reaction temperature 200℃ and reaction pressure 4.5 MPa. The conversion of abietic-type resin acid was 99.37%, and the reproducibility was good. The catalyst could maintain high catalytic activity after 7 times repeated using. X-ray diffraction(XRD), transmission electron microscopy(TEM) and X-ray photoelectron spectroscopy(XPS) characterization showed that the amorphous Ni-P/rGO composite catalyst was successfully prepared, and the Ni-P particles without rGO had larger particle size and poor dispersity. The Ni⁰ content in the composite catalyst decreased relatively after 7 times of use, and the loss of active components caused a slight decrease in catalysis.

Key words: Ni-P, graphene, catalysis, rosin