The Adsorptive And Catalytic Performance Of Modified Graphene

Abstract:Graphene (Gr) is a novel carbon material with many excellent properties. To take full advantage of these properties of graphene and enlarge its application fields, the application performance in heavy metal adsorption and catalyst carrier were investigated on basis of functionalized modification to Gr.Triethanolamine (TEA) and NH2IL (C7H15Cl2N3) were respectively used to modify Gr. The results of FT-IR, UV-vis and XPS analysis showed TEA modified Gr through covalent interaction, and it had plenty of tertiary amine and hydroxyl groups; The NH2IL functionalized modification was completed through non-covalent interaction between imidazole rings and graphitic rings.Then the absorptive property of TEA-Gr on Cu2+was researched. The result showed TEA-Gr had a high adsorption capacity on Cu2+which could be up to3500mg/g. The adsorption process which was divided into two stages could be fitted better by Freundlich model, respectively. TEA-Gr was modified with tertiary amine and hydroxyl which improved binding force and amount of absorptive sites so that it had excellent adsorption ability.In addition, the NH2IL functionalized Gr (NH2IL/Gr) was applied as a carrier coating, and the prepared Gr/palladium/cordierite monolithic catalyst was investigated. To test catalytic performance of the prepared catalyst, hydrogenation of styrene and4-carboxybenzaldehyde (4-CBA) were chosen as the probe reaction. The results showed that modified Gr could be uniformly coated on the surface of cordierite, and the cordierite coated by NH2IL/Gr had a better acid resistance (Soaked in nitric acid solution for8h, the concentration of dissolved Al3+was43.2%of the blank cordierite). The Pd particles on NH2IL/Gr coating had good dispersibility and uniform size, and the average particle size was about4nm. The research of styrene hydrogenation indicated the increased concentration of NH2IL and Gr could both improve catalytic performance, but the higher concentration was not favorable. The stability test of traditional Pd/C and modified Gr prepared catalyst were investigated through4-CBA hydrogenation. The result showed the catalyst activity of the former dropped by almost92%, while the latter was decreased by only30%, which exhibited excellent stability.