Synthesis And Catalytic Properties Study Of Graphene-based Catalysts

Graphene has good electrical conductivity, large specific surface area, whose surface is easily functionalized with acid and alkali. The graphene based materials are considered to be as a kind of very good nonmetallic catalysts and substrate. In this thesis, we design and synthesize a series of graphene-based materials for the oxidation, reduction reactions and electrochemical catalytic field. They showed higher catalytic activity and. the results are summarized as follow:(1) We report an efficient, highly selective, and low temperature graphene-catalyzed reaction process for one-step oxidation of benzene to phenol with hydrogen peroxide as the oxidant. The conversion of benzene reaches18%, with phenol being the sole product. The catalyst was reusable. It was concluded that the moderate H2O2activation rate and good benzene adsorption ability over the oxidation reaction are responsible for the outstanding catalytic performance.(2) Cobalt phthalocyanine/graphene oxide (CoPc-GO) and cobalt phthalocyanine/graphene (CoPc-G) layers were prepared via a simple solvent evaporation method driven by the electronic interaction between cobalt phthalocyanine and graphene oxide. The interaction between cobalt phthalocyanine and graphene oxide has been studied in detail by various methods. The result suggests that the interaction is complicated two-way process including the transfer of electron from the graphitic domain to the adsorbed cobalt phthalocyanine, and a feedback from the Co ions through the ligand-like attacking to oxygen functional groups of graphene oxide. The obtained structural hybrid materials have potential in the electrochemical detection of the compounded medicine. The CoPc-G modified glassy electrode showed excellent response to the electro-oxidation of dopamine.(3) Graphene nanosheets decorated with gourd-shaped Ag nanoparticles (GAg) were prepared from the precursor silver phosphate-graphene oxide nanocomposite (GOAgPO) by original substrate self-generated reduction methods. The material was studied for electrochemical oxidation of glucose in alkaline solution. GAg showed excellent activity at low peak potential. Graphene-supported Pd nanoparticles were prepared by a microwave-assisted reduction approach. The obtained Pd/G can be very effectively coupled to the microwave field, making it a high-performance catalyst for microwave-assisted selective hydrogenation of isophorone at low temperatures. (4) The nickel phosphide graphene nanomaterial (NiPG) was obtained by H2calcination the specific morphology nickel phosphates on graphene oxide (NiPOGO) and graphene (NiPOG) substrate, respectively which were synthesized by one-pot hydrothermal synthesis method. The obtained different structure of nickel phosphates in the same way depended on the influence of different kinds of oxygen-containing groups on graphene substrate. The substrate can also affect the particle size and distribution of nickel phosphates nanoparticles. These materials were employed to be as catalysts for electrochemical oxidation of methanol and the NiPG exhibited high activity. The iron phosphide graphene nanomaterial (FePG) was also obtained by the same method. The Fischer Tropsch Synthesis (FTS) reaction has been selected as model reaction for evaluating FePG.