Effects Of Alloying Elements The Structure And Catalytic Performance Of A Nanoporous PtFe Alloy

Nanoporous metals with nano metal ligament and channel are a new advanced functional material,having wide applications in electrochemical catalysts,supercapacitor and sensor.Dealloying is an effective method for the preparation of nanoporous metals,characterizing simple process and low cost.The amorphous alloy possessing changeable component elements and relatively wide composition ranges has been widely applied in dealloying.The amorphous alloy possessing changeable component elements and relatively wide composition ranges has been widely applied in dealloying.The amorphous alloys possessing homogeneous structure,changeable component elements and relatively wide composition ranges have been highly expected to be an ideal precursor,which is absent of crystalline defects and large scaled phase segregations.As a typical electrocatalyst for methanol oxidation,Pt-based nanoporous alloy is widely used in the field of fuel cell,which are easily poisoned.Works to solve the catalyst poisoning problem have been centered around the addition of co-catalysts and making multiple nanoporous alloy catalyst.we add Ru?Pd,Ag?to Fe-Pt-B amorphous alloy,perpetrating Fe-Pt-M-B?M=Pd?Ag?Ru?amorphous alloy.Then,ternary nanoporous Pt-M-Fe alloys have been fabricated by dealloying Fe-Pt-M-B?M=Pd?Ag?Ru?melt-spun alloy ribbons.The effect of the addition of co-catalysts on the morphology,structure,and electrocatalytic activity of the np-PtFe electrocatalyst has been studied in detail.A novel nano-porous alloy with excellent catalytic performance was developed by optimizing composition.The phase composition,morphology,electrocatalytic activities for methanol oxidation and magnetic properties of the samples were examined by X-ray diffraction?XRD?,transmission electron microscopy?TEM?,scanning electron microscope?SEM?equipped with an Oxford X-ray energy-dispersive spectroscope?EDS?and a standard three-electrode system?Interface 1000?.We tested their magnetic properties by vibrating sample magnetometer?VSM?.The results are as follows:?1?Nanoporous PtPdFe alloys have been fabricated by electrochemical dealloying melt-spun Fe₆₅Pt_10-xPd_xB₂₅?x=0⁵?ribbons,which are composed of a single face-centered-cubic PtPdFe phase.The average pore and ligament sizes are about 6⁷ and7⁸ nm,respectively.The ratio of the peak current density in the forward scan to that in the backward scan?j_f/j_b?is 2.1 and 5.4,respectively.The ternary nanoporous PtPdFe alloys exhibit CO tolerance property in acid solution in comparison with the binary nanoporous PtFe alloy.?2?Nanoporous PtAgFe alloys have been fabricated by electrochemical dealloying Fe₆₅Pt_10-xAg_xB₂₅?x=0²?amorphous ribbons,which are composed of a single face-centered-cubic PtAgFe phase.The ternary nanoporous PtAgFe alloys appear cracking after dealloying with the average pore is about 10 nm.The j_f and j_f/j_b is 0.57 mA cm^-22 and 2.3,respectively.The ternary nanoporous PtAgFe alloys exhibit superior electrocatalytic activity for methanol oxidation reaction and CO tolerance property in acid solution in comparison with binary nanoporous PtFe alloy.?3?Nanoporous PtRuFe alloys have been fabricated by electrochemical dealloying Fe₆₅Pt_10-xRu_xB₂₅?x=0⁴?amorphous alloys,which are composed of a single face-centered-cubic PtRuFe phase.The nanoporous alloys dealloyed from x=0 and 2precursors possess a similar fine bicontinuous ligament/channel structure with average pore and ligament sizes of about 6⁷ and 7⁸ nm,respectively.The structure of the sample?x=4?exhibits coarsening ligaments and uneven nanoporosity.The j_f/j_b is 4.6 and 8,respectively.The ternary nanoporous PtRuFe alloys exhibit superior electrocatalytic activity for methanol oxidation reaction and CO tolerance property in H₂SO₄ solution in comparison with the binary nanoporous PtFe alloy.?4?The Fe₆₅Pt_10-xRu_xB₂₅?x=0⁴?amorphous alloys and nanoporous PtRuFe alloys exhibits soft magnetic characteristics.The saturation magnetization of the precursor varies in a range from 129.3 to132.9 emu/g.The saturation magnetization of nanoporous PtRuFe alloy increases from17.5 to 23.2 emu/g.