| The proton exchange membrane fuel cell(PEMFC)is a highly attractive power source for mobile and stationary applications due to its high power density at lower temperatures and its compact design.At present,the electrocatalyst costs of PEMFC is of high cost that hinder the commercialization of PEMFC.In this paper,we systematically study the electronic structure,physical properties and thermodynamic properties as a function of temperature.And we adopt the characteristic crystal of theory to systematically research on Pt-Ru alloy system.That supply electrocatalyst with complete datum for scientific designation in the light of SSA framework.In this paper,the following researches on Pt,Ru and Pd metals and Pt-Ru alloy system have been performed:(1)By means of MATLAB(MATrix LABoratory), algorithms of single-atom self-consistency method was studied;(2)The electronic structure of Pt,Ru and Pd metals with fcc,hcp,bcc and liquid structure were calculated by using one-atom(OA)method in theory of pure element and one-electron (OE)method that is called first-principle(FP)method.The results were compared each other.The relationship between the crystal structure and electronic structure of Pt, Ru and Pd metals has been analysed.The relationship between the resistivity and chemical activity and the electronic structure of Pt metal has also been analysed.(3) To adopt the theory of pure elements to calculate physical properties and thermodynamic properties as a function of temperature of Pt,Ru and Pd metals,and to get integrate information in the range of OK to melting points Tm.These results were compared with the results of SGTE data,the calculation results by the first principle method and JANAF experimental value.(4)Pt-Ru alloy system was systematically studied by characteristic crystal theory.The atomic volume interacting function and energy interacting function between atoms in Pt-Ru alloy system were determined.The basic information of characteristic atom sequences and characteristic crystal sequence in Pt-Ru alloy system were obtained.(5)We further develop the application of the framework of systematic science of alloys.We brought to light the relationship between the catalytic activity and electronic structure of electrocatalyst, and characterized the structure of electrocatalyst.This will point out the direction of electrocatalyst designation.(6)We apply characteristic atom arranging designing technique and additive law of characteristic crystal to study the catalytic performance and stability of Pt-Ru alloy catalyst,and determine the program about their gradient. (7)We delude the difference between OA method and FP method such as Ni metal and discuss the relationship between the electronic structure and physical properties of Ni,Pd and Pt metal.In this paper,we focused on the research of the relationship among the electronic structure,crystal structure,physical properties,thermodynamic properties and catalytic performance,the results of this paper show that(1)The MATLAB(MATrix LABoratory)software aggregated the strongest value calculation as a tool.The electronic structure of crystal can be determined fast and accurately and consummate single-atom self-consistency method further;(2)The electronic structure of Pt,Ru and Pd metals with fcc,hcp,bcc and liquid structure by OA method and FP method.The results were compared with each other.The result of Pt metal is good agreement with each other,but the results of Ru,Pd metals have great difference.The relationship between the crystal structure and electronic structure of Pt,Ru and Pd metals has been analysed.The relationship between the resistivity and chemical activity and the electronic structure of Pt metal has also been analysed.Due to the least sf electron,the electricity resistance of Pt is biggest,and the chemical activity is the lowest.(3)To adopt the theory of pure elements to calculate physical properties including potential energy curve,thermal linear expansion coefficient,bulk modulus,vibrating energies of lattice,lattice constants and single bond radius and thermodynamic properties including isometric and isobaric heat capacity,enthalpy,entropy and Gibbs energy as a function of temperature of Pt,Ru and Pd metals in the range of OK to melting points Tm.These results were good agreement with the results of SGTE data,the calculation results by first principle method and JANAF experimental value;(4)Pt-Ru alloy system was systematically studied by characteristic crystal theory.The ninth atomic volume interacting function and ninth energy interacting function between atoms in Pt-Ru alloy system were determined.The basic information of characteristic atom sequences and characteristic crystal sequences of Pt-Ru alloy system were obtained. (5)We open up the application of the framework of systematic science of alloys to designation in catalytic material.The electronic structure of phase is approximately substituted to that on the surface.We brought to light the relationship between the catalytic activity and electronic structure of electrocatalyst,When Pt atoms get together,there are 0.5 d electrons transform into s electrons,the number of d-electrons decreases,so increase d-orbital vacancy.It is advantageous to catalytic reaction. Density of state and energy band structure were also used to interpret the catalytic activity by FP method.The result is agreement with the result is characterized by XRD.After addition of another metal,the d electrons of Pt metal transfer to another metal,empty d-orbitals of Pt atom increase,and the lattice constant of alloy decreases, so it is more advantageous to catalytic reaction.This will point out the right direction of electrocatalyst designation.(6)We apply characteristic atom arranging designing technique and additive law of characteristic crystal to study the stability,catalytic performance and gradient composition of Pt-Ru alloy catalyst.The potential energies and lattice constants of Pt-Ru ordered alloy that the ratio of Pt to Ru is respectively 3:1,1:1 and1:3 were calculated.The configuration of component-Pt also had great change which isψ4Pt→ψ8Pt→ψ12Pt.The properties of Pt-Ru disordered alloy and the electronic structure of component-Pt were calculated.As the content of Ru increasing, the potential energies decreases,the stability increase,the lattice constants decrease, and the d-orbital vacancy enlarged,this is advantageous to reaction.But the percentage of Ru surpasses 50%,the d-orbital vacancy enlarged very slowly,this lead to have little influence on reaction.We conclude that the most proper ratio of Pt to Ru is 1:1 from stability,the d-orbital vacancy enlarging value,cost and carbon monoxide tolerant capacity.(7)We delude the difference between OA method and FP method such as Ni metal and discuss the relationship between the electronic structure and physical properties of Ni,Pd and Pt metals,main cause is shield effect of 4f electrons besides influence on electronic structure.
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