Studies Of On Mental-organic Framework Derived Carbons Ethanol Fuel Cell

Currently,the requirement for renewable and sustainable energy sources has increased in importance due to the gradual decline in traditional fossil fuel resources and the detrimental effect of such fuels on the environment.In this context,fuel cells,which are energy devices that directly convert chemical energy into electricity though chemical reactions,have received particular attention due to their high energy conversion efficiencies and low degrees of pollution.However,the high costs and low stabilities of electrode materials have hindered the development of fuel cells,and so to address these issues and improve the catalytic properties of fuel cells,a number of studies have focused on supports.Compared with carbon materials derived from traditional precursors,carbon materials derived from Metal-organic framework(MOF)have obvious advantages,such as high specific surface area and conductivity,controllable porosity,unique morphology and easy functionalization with other heteroatoms.So it has been widely used in energy storage and conversion.The main research content of this thesis is as follows:Direct electron transfer between electrode and biocatalyst is essential for fabrication of enzymatic biofuel cell with high turnover.In the first part of the work,we developed an efficient anode catalyst for alcohol biofuel cell by integrating multi-walled carbon nanotubes into an isoreticular metal organic framework derived porous carbon.The derived porous carbon(PC)intercalated by MWCNTs(PC/MWCNTs)serviced as the anode component in catalyzing the electrooxidation of reduced ?-Nicotinamide adenine dinucleotide(NADH),and led to direct electron transfer catalysis of ethanol electrooxidation with alcohol dehydrogenase.Hierarchy of PC/MWCNTs with micro-,meso-,and macropores provides improved immobilization of electroactive enzymes,aids the facile transportations of electrolyte and increases the conductivity and specific surface areas of anode,resulting in a much higher catalytic current density than its singular component analogues(PC and MWCNTs).The reported PC/MWCNTs modified bioanode outperforms some recently reported mediators included bioanodes,with a relatively high maximum steady-state current density(jpl,max)of 247±25.0 ?A·cm–2.The development of high-performance bifunctional electrocatalysts for fuel cell two half reactions,oxygen reduction reaction(ORR)and methanol/ethanol oxidation reaction(MOR/EOR),is still a major challenge for the commercialization portable electronic equipment.In the second part of the work,we describe a simple method to prepare a class of N-doped carbon nanosheet network,in which Pt Co alloy nanoparticles containing ultralow Pt content are easily convert from traditionalmetal organic framework,denoted as Pt Co@-N/C NS.With the optimized electronic structure and components,the Pt Co@-N/C NS-3 demonstrate the highest catalytic activity for ORR and EOR in various Pt Co@-N/C NS catalysts and commercial Pt/C catalyst.The mass activities of Pt Co@-N/C NS-3 for ORR and EOR are 20.1,and16.3 times than the Pt/C catalyst,respectively.Moreover,Pt Co@-N/C NS-3 is also exhibits super-high stability compared with other Pt Co alloy catalysts reported to date.This work provides us with a simple method to prepare low-cost and high-performance fuel cell catalysts.