Preparation Of PtCr Alloy Electrocatalyst And Its Electrocatalytic Performance Study For Methanol And Ethanol Oxidation

In recent years,extensive academic research has been carried out on direct alcohol fuel cells(DAFCs)using methanol and ethanol as fuel.However,one of the main problems restricting the development of DAFCs is the poor performance of electrocatalysts.Because the electrocatalytic performances of methanol and ethanol oxidation reaction are relatively complicated,it is difficult to completely break the C-C,C-O chemical bonds under the catalysis of Pt,and the energy in the fuel cannot be completely released,which leads to the decrease in the use efficiency of DAFCs.(1)In this work,PtCr/C nanoalloy electrocatalysts were successfully prepared by one-pot carbonization.XRD,FESEM,TEM were used to characterized the structural character.Crystal structure and surface chemical state of the alloy nanoelectrocatalyst were carried out by XPS.The results show that there are two phase in the PtCr/C nanoalloy electrocatalyst-CrPt and Cr3C2,and the carbon support is graphitized.The nanoparticle size of the catalyst exhibited by FESEM observation was about 62 nm and distributed uniformly CV method were used to analyze the electrocatalytic activity,stability and anti-CO poisoning ability of PtCr/C nanoalloy electrocatalyst.PtCr/C-45%catalyst exhibited the best MOR/EOR electrocatalytic activity and anti-CO poisoning ability,its MOR peak current density was 603.74 mA mg-1pt,and the peak current density in EOR was 1081.1 mA mg-1pt,and the peak current density in CO stripping test reached 141.78 mA mg-1 pt,and the ECSA-CO reached 62.46 m2 g-1.All the electrochemical performances were higher than those of the commercial-Pt/C ETEK catalyst.Therefore,this preparation method promotes the development of DAFCs electrocatalyst to some extent.(2)Solvothermal method of metallic organic precursors' reduction successfully prepared PtCr-Mo/MWCNTs nanocomposite catalysts with nanocubic structure.The PtCr-Mo/MWCNTs nanocomposite catalyst was characterized by XRD,FESEM,TEM and XPS.The PtCr-Mo nanoparticles prepared wered uniformly dispersed in multi-walled carbon nanotubes(MWCNTs).On the MWCNTs surface,the diameter of the nanoparticles is approximately in the range of 3 to 5 nm.The XPS results show that Mo is only surface doped with PtCr particles.Electrochemical performance test results show that the PtCr-Mo/MWCNTs nanocomposite electrocatalysts with Mo doping have higher ECSA of H-adsorption/desorption and CO-stripping.In MOR/EOR,the electrocatalytic activity,cycle stability and anti-CO poisoning ability of PtCr-Mo/MWCNTs were greatly improved.The method of preparing electrocatalyst with MWCNTs support by solvothermal reduction has a good application prospect.