Preparation Of Metal Nanoparticals/Expand Graphite Composite Modified Electrode And Application In Electrocatalytic Aspects

In the 21st century,the energy crisis and environmental pollution are both severe challenges faced by human society.The development of clean,efficient energy and energy conversion technologies/systems can bring hope to solve this problem.Fuel cell is a kind of energy converse device,which can convert directly chemical energy of the fuel into electrical energy.They have shown characteristics of low operating temperatures,easy handling,simple,environmentally friendly,non-polluting and so on.As we all know,platinum?Pt?Platinum has been widely used as the anode catalyst for fuel cell.However,expensive price and susceptible to CO poisoning of Pt metal,resulting one of the important issues which has made it difficult to commercialize.Therefore,conduction of fuel cell have always been the research hotspots by improving the utilization rate of catalysts,reducing the cost of catalyst and increasing conductivity of the catalyst support.This paper mainly have studied on the following aspects:the one is prepare the carbon materials as catalyst support with large surface area,high conductivity,good physical/chemical stability and more defect sites,which is good for loading catalyst and improving the catalytic active site.The second is develop new metal electrocatalysts to replace the Pt catalyst is important.Palladium?Pd?have proved promising catalyst for electrocatalytic oxidation of fuels with lower cost and outstanding catalytic activity.The third is introducing other metals form alloy catalyst.Dissociation of carbon monoxide leading to decrease catalytic activity of Pt and active sites.In this paper,we mainly used electrochemical technology to catalyzing organic small molecules?methanol,ethylene glycol,formic acid,formaldehyde,etc?.Metal nanoparticles and nano-materials composites modified electrodes with superior performance were prepared by using chemical and electrodeposition methods.Electrocatalytic oxidation of organic small molecules?methanol,ethylene glycol,formic acid,formaldehyde,etc?was successfully achieved.After a preliminary study,the modified electrode has excellent detection effect for electrocatalytic oxidation of various organic small molecules.The main content of the experiments are summarized as below:?1?Electrocatalytic Oxidation of Formic Acid on Palladium Nanoparticle/Boron Doped Composite Modified Electrode:a boron-doped expanded graphite nanocomposites?B-EG?was prepared as a catalyst support,sodium borohydride as a reducing agent and PdCl₄^2-was reduced as a catalyst.In addition,Pd-NP/B-EG nanocomposites with different mass fraction Pd were achieved.The electrocatalytic oxidation of formic acid in alkaline medium was studied.The results showed that Pd-NP/B-EG nanocomposites has good electrocatalytic activity for formic acid.?2?Platinum-palladium nanoparticle/boron doped composite modified electrode electrocatalytic oxidation of methanol:Boron-doped expanded graphite nanocomposites were prepared to increasing the defects of materials and enhancing the electron transfer rate.The PdPt-NP/B-EG nanocomposites has been prepared on the above B-EG using sodium borohydride as the reducing agent.Different mass fraction ratio of Pd-NP and Pt-NP as a catalyst.The best Mass fraction ratio of PtPd?1:1?-NP/B-EG coated electrode was selected in alkaline medium for electrocalalytic oxidation of methanol.Electrochemical results showed that PtPd?1:1?-NP/B-EG has good electrocatalytic oxidation activity,anti-poison property and stability to methanol.?3?Expanded Graphite and Carbon Nanotubes Supported Palladium Nanoparticles for Electrocatalytic Oxidation of Liquid Fuels:An expanded graphite-multiwalled carbon nanotube?EG-MWCNTs?nanocomposite with large specific surface area was prepared as a catalyst support,Palladium nanoparticles?Pd-NP?were loaded onto the EG-MWCNTs nanocomposites by electrodeposition.The prepared nanocomposites were characterized by SEM,TEM,XRD,EDX and electrochemical methods.Five kinds of liquid fuels?methanol,ethanol,ethylene glycol,formic acid and formaldehyde?were selected from the best proportion of EG-MWCNTs nanocomposites to study the electrocatalytic oxidation of alcohols in alkaline medium.The results showed that the Pd-NP/EG-MWCNTs composite material has good electrocatalytic oxidation activity and better anti-poisoning properties for alcohols.