Preparation And Performance Study Of Anode Catalyst For Direct Methanol Fuel Cell

Direct methanol fuel cell is a new type of energy system.Compared with traditional battery system,it has the advantages of less energy loss,wide fuel source,safe fuel transportation,and green environmental protection.However,the cost,catalytic activity and catalytic stability of the catalyst have limited the commercial development of direct methanol fuel cells.At present,the preparation of new anode catalysts with high catalytic activity and high stability is a research focus of fuel cells.In this study,cyclic voltammetry was used to deposit active metals on carbon nanotubes and composite supports.A methanol fuel cell catalyst with high efficiency and low platinum loading was prepared and its performance was studied.The research content is as follows:1.In the preparation process of the carrier,the ratio of carbon nanotubes and titanium dioxide?1%,3%,5%,7%,9%,11%?,the prepared pH?1-7?and the aging temperature?25?-65??and other conditions were studied,and the best conditions for carrier preparation were determined by TEM,thermogravimetry,infrared,BET and other characterization methods.When the carbon nanotubes and titanium dioxide are 5%,by adjusting pH=3,after aging at25°C and calcination at 450°C,a catalyst support with a specific surface area of up to 3136.582m²/g is obtained.2.Cyclic voltammetry was used to investigate the catalytic effect of single carrier CNT loaded with single metal and bimetal.The addition of the second metal has improved the catalytic activity and stability of the catalyst.At the same time,the effect of the composite carrier CNT@TiO₂ on the catalytic performance of the catalyst prepared under single metal and bimetallic conditions was also explored.Studies have shown that the addition of metallic Co can effectively improve the catalyst stability and catalytic activity.3.The effect of the main salt metal ratio on the electrodeposition of PtTi-CNT and PtCo-CNT@TiO₂ was investigated;when the metal ratio Pt:Ti=1:2,the catalyst showed excellent catalytic effect,Electrochemical catalytic current reaches 25.08 mA/cm^2..At the same time,in the composite carrier,as the metal ratio increases,the catalytic performance of the catalyst increases first and then decreases.When the metal ratio Pt:Co=1:3,the catalyst electrochemical catalytic current can reach 21.42 mA/cm^2.4.The prepared catalyst was characterized by TEM,XRD,thermogravimetric analysis and other methods,and the relevant data of the catalyst particle size and heat resistance were obtained.The research shows that the composite carrier is more resistant to high temperature,acid and alkali than the single carrier catalyst.5.Using an electrochemical workstation,the electrochemical behavior of PtTi-CNT was studied,and the catalytic ability of the catalyst to alkaline methanol solution under different catalytic conditions was investigated.At the same time,the electrochemical stability of the catalyst was measured by the chronoamperometric method.Studies have shown that the catalytic activity of bimetals is 16.76mA/cm² higher than that of single metals.Bimetallic catalysts show higher current values than single metal catalysts,indicating that they have higher stability.6.The electrochemical analysis of the catalytic performance,electrochemical activity and stability of the PtCo-CNT@TiO₂ catalyst prepared under different conditions shows that the composite carrier added with oxide can effectively improve the stability of the catalyst,and with the As the scan rate increases,the composite carrier exhibits a lower correlation between the peak of the catalytic current and the first half of the scan voltage compared to the single carrier.