Preparation And Electro-catalytic Performance Research Of Two-dimensional Nanomaterials

Due to the depletion of global fossil energy resources and the worsening of environmental pollution,people urgently need to find a clean and efficient new environmental protection energy.Compared with fossil energy,fuel cell is a kind of device that converts chemical energy directly into electrical energy,which has been developed unprecedently in recent years due to its clean and efficient characteristics.As a new type of fuel cell,direct alcohol fuel cell has many advantages,such as wide fuel source,low cost and easy to carry,so in many fields such as power and catalytic widely attention and research.At present,the cost and durability of fuel cell are the bottleneck of direct alcohol fuel cell,among which catalyst is one of the most important factors.With the continuous research and application of catalysts,in order to reduce the cost of catalysts,palladium,which is relatively low price,is gradually used to replace platinum in the selection of precious metals.On the other hand,in order to further improve the performance of the catalyst,the catalyst support developed from a single material to a multi-component composite,which is because the composite can make up the defects of the single material.It also helps to form the synergistic effect between the components,thus enhancing the catalytic performance.As a result,the des ign of surface and interface of catalytic materials plays an increasingly important role in the optimization of catalyst performance.In this paper,palladium nanoparticles loaded on different supports were prepared as anode catalysts for direct ethanol fuel cells,and their electrooxidation properties for alkaline ethanol were tested.The main conclusions of this paper include the following aspects:I.Preparation and electrocatalytic properties of titanium dioxide black phosphorus composite supported palladium catalyst.In this chapter,we used anatase titanium dioxide nanosheets?ATN?and black phosphorus?BP?to prepare titanium dioxide black phosphorus composite material?ATN-BP?as a support of electrocatalyst by mechanical ball-milling method.Next,a certain amount of the ATN-BP was dispersed in Na₂Pd Cl₄solution.Then,we added moderated KBH₄ as the reducing agent.Finally,Pd/ATN-BP was prepared by impregnation reduction methods.The results showed that the oxidation current density of Pd/ATN-BP in 1 M NaOH and 1M C₂H₅OH solution reached 4952.9 mA mg^-1,which is almost 6.78 times higher than the traditional commercial catalyst(Pd/C,20 w.t%,730.7 mA mg^-1).Besides,Pd/ATN-BP processed great stability toward EOR and the current density at 3600 s remained at 867.7 mA mg^-1,which is almost 40.7 times higher than Pd/C.It was proved that titanium dioxide black phosphorus composite supported palladium catalyst had great electrooxidation activity and stability.II.Preparation and electrocatalytic properties of activated graphene black phosphorus heterostructures supported palladium catalyst.In this chapter,we used activated graphene?AG?and black phosphorus?BP?to prepare activated graphene black phosphorus heterostructures material?AG-BP?as a support of electrocatalyst by mechanical ball-milling method.Next,a certain amount of the AG-BP was dispersed in Na₂Pd Cl₄ solution.Then,we added moderated KBH₄ as the reducing agent.Finally,Pd/AG-BP was prepared by impregnation reduction methods.The results showed that the oxidation current density of Pd/AG-BP in 1 M NaOH and 1 M C₂H₅OH solution reached 6004 mA mg^-1,which is almost 7.19 times higher than commercial Pd/C(834.5 mA mg^-1).Besides,Pd/AG-BP processed excellent stability toward EOR and the current density at 20000 s remained at 712.03 mA mg^-1,which is almost 80.3 times higher than Pd/C.It was proved that activated graphene black phosphorus heterostructures supported palladium catalyst had excellent electrooxidation activity and stability.III.Preparation and electrocatalytic properties of activated graphene nitride nickel composite supported palladium catalyst.In this chapter,we used activated graphene?AG?and nitride nickel?Ni₃N?prepare activated graphene nitride nickel composite material?AG-Ni₃N?as a support of electrocatalyst by mechanical ball-milling method.Next,a certain amount of the AG-Ni₃N was dispersed in Na₂Pd Cl₄ solution.Then,we added moderated NaBH₄ as the reducing agent.Finally,Pd/AG-Ni₃N was prepared by impregnation reduction methods.The results showed that the oxidation current density of Pd/AG-Ni₃N in 1 M NaOH and 1 M C₂H₅OH solution reached2658.5 mA mg^-1,which is almost 3.98 times higher than commercial Pd/C(668mA mg^-1).Besides,Pd/AG-Ni₃N processed good stability toward EOR and the current density at 3600 s remained at 464.45 mA mg^-1,which is almost 26.5times higher than Pd/C.It was proved that activated graphene black phosphorus composite supported palladium catalyst had good electrooxidation activity and stability.