Preparation And Application Of Hierarchical Porous N-doped Carbon Materials And Noble Metal Supported Catalysts

Carbon-based materials have attracted great attention in many fields due to their unique features of low cost,high specific area,superior chemical/physical stability,non-toxic and porous structure.Introduction of nitrogen-species on the skeleton of carbon materials has recently been proved to be an efficient way to enhance the performance of carbon materials.With characteristics of basic properties,enhanced hydrophilicity and more active sites,N-doped carbon materials have shown promising applications in energy storage,electrocatalysts and catalyst support.On the other hand,hierarchical porous structure has shown beneficial effect on improving mass transfer in the energy storage and catalysis application.Thus,developing a simple and efficient method to synthesis carbon materials with high nitrogen content,high surface area and hierarchical porous structure simultaneously is of great importance.The focus of this thesis mainly lies in design of nitrogen doped hierarchical porous carbon materials and application of them in energy storage and catalysts support as well as developing a facile solvent-free method to prepare high-efficiency highly dispersed noble metal supported catalysts.The detailed research works in this thesis are listed as follow:(1)An efficient incipient wetness method was explored to prepare N-doped hierarchical porous carbon materials(NHPCs)with N-enriched Schiff-base copolymer as precursor and MgO as template.The final obtained NHPCs-700 possesses high specific surface area(904 m2/g),highly N content(10 wt.%),graphitic structure and hierarchical pores.Benefiting from the synergistic effects of these unique features,the obtained NHPCs-700 achieves excellent supercapacitor and lithium-ion battery performances including high capacity(419 F/g at 0.5A/g for supercapacitor)and(2722 mAh/g at 100 mA/g for Li-ion battery),superior rate capability and cycling stability,indicative of a promising candidate for next generation energy storage and delivery devices.(2)Bi-metallic PdAu/CN catalysts were prepared by a simple impregnation method with the obtained NHPCs-700(CN)as support and their catalytic performance overphenol hydrogenation was investigated.Because of the formation of Pd-Au alloy,bi-metallic PdAu/CN catalysts showed higher activity,higher selectivity and good stability towards phenol hydrogenation than Pd/C A and Pd/CN.(3)A facile solvent-free solid state dispersion method was developed to prepare highly dispersed Pd/HAP(hydroxyapatite)catalyst.The further catalytic investigation show that the solvent-free method derived catalysts exhibited a smaller particle size(1.2 nm)and a higher catalytic activity than the reference catalyst prepared by a conventional impregnation method on phenol hydrogenation to cyclohexanone and hydrogenation of acetylene to ethylene.