The Study On The Electrocatalyst For Oxygen Reduction Reaction From Soybean

Fuel cell is the most promising new green energy as its advantages of clean andhigh efficient. The development of catalysts for oxygen reduction reaction in airelectrode is the key factor for the fuel cell energy conversion’s improvement. Nowmainly Pt-based catalyst is used for fuel cell. However, Pt’s high price, resource scarcity,and easy to be poisoned has limited its commercial application. Therefore, the study ofnon-precious metal TM-N/C catalysts with low cost and good catalytic activity is ofgreat significant.In this thesis, nitrogen-rich biomass soybeans is used as N source. The TM-N/Ccatalysts were prepared by MgO templates method and two-step pyrolysis method. Theeffect of the addition amount of magnesium acetate, transition metal loading, the heattreatment temperature and time in the process of catalyst’s preparation on catalystperformance were explored. While LSV was used to evaluate the catalyst activity andstability, and the catalyst structure was characterized by XRD and TG/DTG.It is found that the activity of catalyst is indeed improved by MgO templatemethod. The performance of SB/C and CoSB/C catalysts have been improved afteradding magnesium acetate. When mass radio of Mg(CH3COO)24H2O and SB is1:1,the catalyst has the best electrocatalytic activity. The results of XRD and TG/DTG showthat magnesium acetate begin to decompose and form magnesium oxide with largequantity at350℃. Two-step pyrolysis method is based on MgO templates, and its aim isto separate the magnesium oxide forming process and the metal involved catalyticactive sites formation process. The experimental results show that CoSB/C(T1-T2) madeby two-step pyrolysis method has better activity and stability than CoSB/C(MgO).The experimental results demonstrated that metal loading has great influence onthe catalyst TM-N/C’s activity. The LSV test of acid-leaching CoSB/C (MgO) catalystshowed that the metal Co is not catalyst active sites, but it may promote the formationof catalytic active sites. Co%(m/m)=14%~16%, is the optimum metal loading. Inaddition, the experiments also confirmed that the heat treatment temperature that neededfor catalytic activity sites formation should be greater than600℃. For the CoSB/C(T1-T2) catalyst, the optimal prepared conditions is pre-treatment2h in400℃, and heattreatment2h in900℃. The onset reduction potential and peak potential of the catalysts prepared in this best condition are0.01V and-0.084V, respectively.