Study On The Preparation Of Ni-B/rGO Catalyst And The Hydrogenation Reaction Of Rosin

Rosin is a natural resin widely found in nature and a valuable chemical raw material.The main component is a phthalic acid type resin acid,and the citric acid type resin is chemically active,and can be subjected to various chemical reactions to form various industrial raw materials.Industrial hydrogenated rosin is generally produced by hydrogenation of rosin.It is widely used in industrial sectors such as adhesives,synthetic rubber,paints,inks,etc.Research and preparation of high performance catalysts for hydrogenation of rosin is of great sigNificance for deep processing and utilization of rosin.Graphene is a new two-dimensional material with high specific surface area,easy dispersion,high mechaNical properties and thermal stability.There are some carbon vacancies and unreduced oxygen-contaiNing groups on the surface of graphene prepared by chemical methods.This is not conducive to electron transfer,but it has uNique properties for the synthesis of metal-graphene materials in the catalytic field,and the combination of graphene and nanoparticles can effectively reduce the ?-? stack between graphene layers,thus making it It is not easy to agglomerate,and the nanoparticles also have a synergistic coupling effect,which is advantageous for preparing a catalyst with high dispersibility and high catalytic performance.Diversification of a single graphene by modification or recombination makes graphene an excellent carrier material.Therefore,the Ni-B/rGO composite catalyst was prepared by microwave reduction with chemical reduction method for catalytic hydrogenation of rosin.The specific experimental content is as follows:(1)Graphene oxide was prepared by modified Hummers method,and Ni-B/rGO composite catalyst was prepared by one-step chemical reduction under microwave assist.The optimum preparation conditions were obtained by single factor experiment and orthogonal experiment: Ni/B molar ratio was 1:5,preparation temperature was 70 °C,sodium borohydride solution pH=1,and mass ratio of GO to Ni was 1:7.By analyzing the FT-IR image,XRD pattern and TEM image,it can be proved that the graphene oxide is successfully prepared,and the graphene oxide can be reduced to reduced graphene oxide by adding sodium borohydride by XRD,TEM,XPS,etc.It can be known that Ni-B and rGO were successfully combined to successfully prepare Ni-B/rGO composite catalyst.(2)The catalyst obtained by the above optimal preparation conditions was applied to the catalytic hydrogenation of rosin,and the conditions of catalytic hydrogenation of rosin were optimized by single factor and BDD response surface methodology.The optimal preparation conditions were as follows: 200 ° C,the reaction pressure was 4.5 MPa,the reaction time was 4 h,and the amount of the catalyst was 5% by weight of the raw material rosin.Three reproducibility experiments were carried out,and the average conversion rate of rosin catalytic hydrogenation was 99.72%,and after using the catalyst for 7 times,there was still higher activity.The hydrogenated rosin obtained after the reaction reaches the national standard for hydrogenated rosin(according to GB/T 14020-2006).(3)Qualitative and quantitative analysis of hydrogenation products by gas chromatography and gas chromatography-mass spectrometry,characterization by FTIR,XRD,TEM and XPS,not only proved successful synthesis of Ni-B/rGO composite catalyst According to the characterization results of TEM and XPS,the Ni-B/rGO composite catalyst has better dispersibility than the Ni-B nano-alloy;the catalyst deactivation is caused by the oxidation of the active component Ni0 to Ni2+;the deactivation of the deactivated catalyst.Poor,partial agglomeration occurs;the catalyst after multiple reactions can see edge crystallization in HRTEM.