Transition Metal Sulfide Carrier Assisted Methanol Electrooxidation Performance Research

The rapid development of industrial production makes the human increasingly demand for energy.The massive exploitation and utilization of traditional fossil fuels?coal,oil and natural gas,etc.?have dramatically reduced their reserves and caused enormous damage to the natural environment.Therefore,seeking an environmentally friendly energy source to gradually replace fossil fuels is an effective way to mitigating energy and environmental problems.Direct methanol fuel cell?DMFC?has the advantages of renewable fuel,low cost,high safety,high energy density and convenient storage and transportation.It is considered as a very promising technology for clean energy utilization.However,the poor stability,easy CO poisoning and high price of anode Pt catalyst have seriously hampered the practical application of DMFC.Several studies have shown that co-catalysts can effectively improve the stability and anti-toxicity of Pt-based catalysts to enhance methanol oxidation reaction?MOR?activity.To solving these shortcomings,we prepared and studied the catalytic performance of the transition metal sulfide as supports for anode catalyst of DMFC,which preform high stability,high toxicity and high MOR catalytic activity.And the main research contents and results are as follows:By changing the mass ratio of MoS₂ and nitrogen doped-carbon?CN_X?,a MoS₂/CN_X composite with coral-reef like structure is prepared by one-step hydrothermal method and used as a carrier and/?or?co-catalyst for the Pt?5 wt.%?based catalyst for MOR.The foamed nickel?NF?is used as a substrate for preparing Mo-doped Ni₃S₂ nanorods?MoS₂/Ni3S₂-nrs/NF?composite in varied amount of Mo source,which is further synthesized as a Pt?0.5 wt.%?support and/?or?co-catalyst for MOR.The experiments show that under acidic conditions Pt/MoS₂/CN_X exhibits high methanol oxidation activity and its electrochemical surface area and mass specific activity are 111.2 m² g_Pt^–11 and 1030.2 mA mg_Pt^–1,respectively,and also show good stability.These properties are far superior to commercial 10 wt.%Pt/C(mass specific activity 405.4 mA mg_Pt^–1).Under alkaline conditions,Pt/MoS₂/Ni₃S₂-nrs/NF(805.4 mA mg_Pt^-1)exhibited much higher mass specific activity than commercial Pt/C?10 wt.%?(408.8 mA mg_Pt^–1).In addition,Pt/MoS₂/Ni₃S₂-nrs/NF also exhibits extremely strong MOR stability.According to theoretical calculations,this can be attributed to the extremely strong binding of Ni₃S₂ to Pt nanoparticles?Pt NPs?,which effectively prevented Pt NPs from falling off and migration agglomeration during the MOR process.In addition,the interaction between MoS₂ NPs,Ni₃S₂-nrs,and Pt NPs further improves the dispersion of Pt NPs.These changes in properties of this catalyst all effectively increase its MOR activity and stability.