Nitrogen-doped Carbon Prepared From Biomass And Its Application In Electrocatalytic Reaction

Catalyst is the major part in fuel cells?FCs?. However, the high cost and poor stability caused by the using of Pt catalyst, is the main reason to obstruct commercialization of the FCs. Therefore, researching and developing inexpensive electrocatalysts with high activity is the inevitable choice for achieving the commercialization of FCs. The electrocatalysts in FCs mainly concentrated on developing novel catalyst to decrease or replace Pt-based catalyst. Especially,nitrogen doped carbon has became a research hotspot in recent years. Nevertheless,using of abundant and renewable biomass as raw materials to prepare biomass-derived nitrogen doped carbon based catalysts is rarely studied.This paper focused on using biomass to modify or prepare nitrogen doped carbon.Then, they were used as catalyst support or non precious metal catalyst in alcohol oxidation and oxygen reduction reaction?ORR?. The structural properties were characterized by Raman, X-ray diffraction?XRD?, Transmission electron microscopy?TEM?, X-ray photoelectron spectroscopy?XPS? measurements and so on. The electrochemical performance towards alcohol oxidation and ORR were estimated by cyclic voltammograms?CV?, linear sweep voltammetry?LSV? and chronoamperometry?CA?. The main points of this thesis include three parts. The specific contents are as follows:Part I: Pd₃Ni nanoparticles supported on carbonized 1,10-phenanthroline modified carbon support: A highly efficient electrocatalyst for methanol oxidationTo combine the advantages of nitrogen doped carbon support and Pd₃Ni alloy nanoparticles, firstly, nitrogen doped carbon?PMC? was obtained by carbonized the mixture of 1,10-phenanthroline and carbon black. Then, the PMC was used as support to load Pd₃Ni alloy nanoparticles?Pd3Ni/PMC?. And the Pd3Ni/PMC was used for methanol oxidation reaction?MOR?. The structural properties of Pd3Ni/PMC were characterized by XRD, TEM and XPS. Because of the nitrogen modified support and Pd alloying with Ni, electrochemical tests illustrate that, compared to conventional Pd/C and Pd/PMC catalysts, the Pd3Ni/PMC catalyst exhibits better electrocatalytic activity and stability for MOR. Kinetic studies also show that the apparent activationenergy for Pd3Ni/PMC is only a half Pd/C counterpart in MOR.Part II: Nitrogen doped carbon prepared from riboflav and its application in ethylene glycol oxidationChoosing riboflav as nitrogen source. After the riboflavin was preliminary treated with sulfuric acid, biomass-derived nitrogen-containing carbon?R-C? was prepared from riboflavin by thermal treatment and used as support to immobilize Pd nanoparticles?Pd/R-C?. Structural characterizations demonstrate the introduced nitrogen atoms in carbon support effectively improve the particle size and dispersion of Pd nanoparticles. Then, Pd/R-C was used for ethylene glycol oxidation?EGOR? in alkaline media. The electrochemical measurements shows that Pd/R-C exhibits excellent electrocatalytic activity and stability for EGOR. Meanwhile, the effects of temperature, scan rates and electrolyte concentration were investigated and the mechanism of catalytic reaction was discussed.Part III: Nitrogen doped carbon-based catalyst prepared from chitosan and its application in oxygen reduction recationBiomass derived nitrogen doped carbon has been prepared by carbonized the mixture of chitosan?CS? and phenolic resin. Here, CS, a available and cheap derivative of biomass, as the nitrogen precursor and phenolic resin as carbon precursor. After acid treatment, a serious of catalysts with different atom ratio?C:N?were obtained. They were used as non-precious catalyst for ORR in alkaline media.The ORR test demonsrates the CN?2:7? shows the best catalytic activity. Compared to Pt/C, CN?2:7? possesses better stability and methanol tolerance. Accordingly, the structure of CN?2:7? was characterized by Raman, XRD, Nitrogen adsorption?BET?,Scanning electron microscope?SEM? and XPS measurements. These indicate that CN?2:7? prepared from chitosan is promising to replace Pt-based catalysts and could become a novel ORR catalyst in FCs.