Ta₂O₅/MWCNTs Loaded Platinum-based Catalyst And Its Properties Of Electrocatalytic Methanol

Direct Methanol Fuel Cells is a power generation device that converchemical energy into electric energy.However,the problem of Direct Methanol Fuel Cells anode catalysts is low activity,low stability and expensive price.To solve these problems,this paper focuses on the influence of the cocatalyst on the catalytic reaction.And studied the effect of doping on the catalyst.The prepared catalysts showed high catalytic activity and stability compared with commercial Pt/C.The specific research work includes the following aspects:(1)Prepared the Pt/Ta2O5/MWCNTs catalyst.The electrochemical activity and electrochemical stability of the Pt/Ta2O5/MWCNTs catalyst were also studied.The physical structure was characterized by XRD,Raman,TEM,and XPS.The electrochemically characterized by ESA,MOR,I-t,and Tafel curve.The average particle size of the Pt and Ta2O5 nanoparticles was 2.8 nm.The electrons were transferred from Ta2O5 to Pt.Promoting the generation of the Pt0.Electrochemical studies have found that Pt/Ta2O5/MWCNTs has a higher electrochemical active surface area,higher electrocatalytic activity,and better stability.Ta2Os oxidized the COads,protecting the Pt from being poisoned by the COads.(2)Doped La to the Ta2O5 by Hydrotherimetry.Prepared the Pt/Ta2O5-La/MWCNTs catalysts.The electrochemical properties and electrochemical stability of the Pt/Ta2O5-La/MWCNTs catalyst are studied,and the effect of lanthanum doping on the catalyst is discussed.Experiments show the La-25%has the best performs.XRD demonstrated that the successful doping of La.TEM demonstrates that the particle size of the catalyst nanoparticles about 4.8 nm.XPS found that the electrons were transferred from Ta2O5 and La to Pt,contributing to the generation of Pt0.Electrochemical studies have found that the Pt/Ta2O5/MWCNTs has a higher electrochemical active surface area,higher electrocatalytic activity,and better stability.The doping of La improves the conductivity of the Ta2O5 and increases the ability of the catalyst to escape from the COads.(3)Doped Te to the Ta2O5 by sodium subphosphate reduction and preparing the Pt/Ta2O5-Te/MWCNTs catalysts.The electrochemical properties and electrochemical stability of the Pt/Ta2O5-Te/MWCNTs catalyst are studied,and the effect of Te doping on the catalyst is discussed.Experiments show the Te-20%has the best performs.XRD demonstrates that the Te has been successfully doped into the Ta2O5.TEM demonstrated that the particle size of catalysts is between 2 nm and 10 nm.XPS shows that the transfer of electrons from Ta2O5 to Pt and Te which contributes to the generation of Pt0 and Te.Thus improving the utilization of platinum in the catalysts.The doped of Te reduces the size of the catalyst particles,enhancing the electrical conductivity of the Ta2O5,and Ta2O5 playing a greater role in catalytic reaction.