Preparation And Performance Study Of Non-platinum Catalysts For Direct Methanol Fuel Cells

Direct methanol fuel cell(DMFC)has the advantages of low operating temperature,clean and pollution-free,high energy density is considered the most likely to commercialize the battery,hoping to be used in clean energy vehicles,portable power supply and so on.Currently,the major problem affecting the commercialization of direct methanol fuel cells is the use of expensive platinum-based catalysts for cathodic oxygen reduction(ORR).In the absence of platinum resources,the cost of catalysts can not be reduced by mass production.Therefore,the development of non-noble metal cathode catalysts that are resource-independent and inexpensive has been extremely important for the development of direct methanol fuel cells.This paper focuses on the development of direct methanol fuel cell cathode non-platinum cathode catalyst to further improve the catalyst for oxygen reduction activity.The advantage is that the carbon material has good conductivity as a skeleton and the structure is relative stable.The reseach work were done as followings:In this paper,GOx-CeO2 NWs composite catalyst with ceria nanowire intercalated graphene structure was prepared as ORR electrocatalyst by simple hydrothermal method.When the mass ratio of GO to CeO2 nanowire is 3:1,the GO3-CeO2 nws composite catalyst exhibits a high ORR due to the availability of CeO2NWs not only as an effective catalyst but also as an "oxygen buffer" for alleviating ORR oxygen deficiency Catalytic performance and good stability:Good initial electric potential of 0.91 V,high ultimate current density and good methanol tolerance at 1600 rpm;at the same time its kinetics the Tafel slope is 56.0 mV dec-1,Much lower than that of CeO2 NWs,pure GO and Pt/C,indicating that the GO3-CeO2 NWs composite catalyst has a better kinetic process,that is,the oxygen reduction reaction is easier to carry out.A Co/KB@MOF derived electrocatalyst was designed a using MOFs as a sacrificial template and assembling a Co-ZIF-67 metal organic framework on on Ketjen black EC-600JD(KB)carbon black and calcining the pyrolysis in a N2 atmosphere.As in the preparation process,pyrolytic calcination led to a large number of pyridine nitrogen and coordination nitrogen ORR activity center point,coupled with KB has good conductivity,can overcome the shortcomings of poor electronic conductivity ZIF-67 derivatives,so that It exhibited good ORR electrocatalytic activity in alkaline media with an initial potential of 0.96 V and a half-wave potential(E1/2)of 0.86 V and was superior to long-term stability and methanol resistance of commercial Pt/C.