Study On Transition Metal Carbides As Electro-catalysts

Fuel cells are known for being green and efficient.Fuel cells have attracted the attention of researchers,But the cathode oxygen reduction reaction(ORR)that restricts its development.Transition metal carbide has been applied to ORR because of its properties of precious metals.This paper deals with the study of low-platinum(Pt)load and non-precious metal iron for transition metal catalysts in ORR.The results were obtained as follows:(1)The Pt-W-C series catalyst was prepared by one-step method.The effect of different carbon carrier and carbide content on catalyst activity was investigated,The test results showed that 5%Pt/15%W/80%BP performance was the best.By contrast test,the ORR performance of 5%Pt/95%BP was verified by the addition of carbide,The initial potential of the catalyst increased by 30mV,The number of electron transfers increased from 2.52 to 3.05.5%Pt/15%W/80%BP and commercial platinum carbon were normalized by Pt quality,5%Pt/15%W/80%BP activity is 2.77 times that of commercial platinum 20%Pt/C(20%quality of Pt)and good stability.(2)The Pt-Mo-C series catalyst was prepared by one-step method.The effect of different carbon carrier and carbide content on catalyst activity was investigated,The test results showed that 5%Pt/30%Mo/65%BP performance was the best.By contrast test,the ORR performance of 5%Pt/95%BP was verified by the addition of carbide,The initial potential of the catalyst increased by 40mV and the half wave potential increased by 60 mV and limiting current density increased by 1.01mA/cm2,The number of electron transfers increased from 2.52 to 3.47.5%Pt/30%Mo/65%BP and commercial platinum carbon were normalized by Pt quality,5%Pt/30%Mo/65%BP activity is 3.23 times that of commercial platinum 20%Pt/C(20%quality of Pt)and good stability.(3)The tungsten modified Fe-W-C and nitrogen modified Fe-N-C catalyst were prepared by one-step method.The effects of carbonization method,carbonization temperature,W,N and the main active substances were investigated.The study found that the nitrogen modified Fe-C-N performance was better.5%Fe-95%N/BP(NH3-600 ?)could match initial potential and half wave potential business platinum carbon,The limit current density of 4.35mA/cm2.Compared with Fe-C catalyst,the initial potential of nitrogen modification catalyst was shifted 120mV,half wave potential was moving 150mV,and the current density increased by 1.1mA/cm2.