Graphitization Of Ordered Mesoporous Carbon And Its Electrocatalytic Performance After Loading With Pt Nanoparticals

Mesoporous materials which have been widely investigated due to its’ high surface areasand pore volume as well as ordered mesostructures, have potential applications as catalysts,separation media, and advanced electronic materials in many scientific disciplines. Our workpivots around modified mesoporous materials as catalyst supports for direct methanol fullcells.Carbon nanotubes/Orderd mesoporpus silica composites（CNTs/OMS） was prepared by usingCTAB as not only exceptionally dispersant of carbon nanotubes in the aqueous phase but also as anorganic template for directing the formation of mesoporous silica. This composites showed highlyconductivity because of CNTs and carbon films coated on orderd mesoporpus silica after calcinedin nitrogen atmosphere. Pt nanoparticles loading on the composites displayed excellent catalyticperformance and stability in sulfuric acid. The electrochemical active surface area （EASA） of thiselectrocatalyst is120.9m²·g^-1.Mesoporous carbon/carbon nanotubes composites replicated from the above-synthesizedCNTs/OMS template by using sucrose as carbon precursors. X-ray diffraction（XRD） andtransmission electron microscope（TEM） showed that this composites has a disordered porestructures. The conductivity of those composites increased with the raised mass ration of CNTs. Ptnanopaticals supported on this carbon composite showed high electrocatalytic activity. The peakcurrent of methanol oxidation by this catalyst is80.3mA·cm-2, and the electrochemical activesurface area is110.9m²·g^-1, which is2.02times than Pt-MC catalyst that without CNTs.When P123was used as organic template for synthesized of CNT/OMSs composite, orderedmesoporous carbon/carbon nanotubes replica （CNT/OMC） was obtained. We finded that theaddition of appropriate CNT had no effection to the ordered mesoporous structure of carbon.Similar to chapter3,the conductivity and plumbaginous degree of CNT/OMC composite is higherthan OMC, which is benefit for loading with Pt nanoparticles. The Pt-CNT/OMC catalyst have ahigher electrochemical active surface area of114.8m²·g^-1than Pt-OMC catalyst, which indicatethat the addition of appropriate CNTs in OMC could improve the performance of Pt nanoparticles.Further more, graphite oxide that full of hydroxyl and carboxyl was doped into orderedmesoporous carbon to improve its’ supporting properties. Glycol can transforme Pt4+and graphiteoxide into Pt and graphene by the microwave-irradiated polyol process. TEM showed that Pt nanopaticles were highly dispered on reduction graphite oxide/ordered mesoporous carboncomposite. The electrochemical active surface area of Pt-RGO/OMC-3catalyst is80.4m²·g^-1. ThePt-RGO/OMC-3catalyst showed higher enhanced catalytic activity than Pt-OMC catalyst.In conclusion, we prepared ordered mesoporous carbon/graphitization carbon composites byhard template method. Graphitic carbon, including cabon nanotubes and graphite oxide， can bothenhance the graphitization degree and hydrophilia of these composites. Thus the catalyst showedhigh electrochemical performance and durability.