Preparation And Electrochemical Performance Of Platinum-nickel Carbon Composite Catalyst

Catalysts have an important and wide application in chemical industry.Such as the production of fertilizers,pesticides,a variety of chemical materials and so on,the development and utilization of clean energy and the living environment of human governance and protection.Therefore,It is of great significance to design and synthesize a new catalyst.In order to meet the market demand for catalysts and energy issues,we designed and synthesized carbon supported platinum-nickel composite catalysts with different microstructures,which were used for the study of ethanol electrocatalytic oxidation and ethanol sensing.In this work,platinum nanoparticles were deposited on a carbon carrier with the partly graphitized carbon and the highly dispersive carbon-coated nickel particles by chemical reduction method.A catalyst with efficient electron transfer structure was fabricated by controlling the contents of the deposited platinum.The high resolution transmission electron microscopy images of Pt2/Ni@CN-doped sample show a highly efficient electron transport pathway in which reactants react at the Pt plane and the lost electrons migrate from the Pt(111)plane to graphite(100)or Ni(111)crystal plane.The Pt3/Ni@CN-doped with low Pt contents have heterogeneous dispersed and cannot form the electron transfer structure and the Pt1/Ni@CN-doped with high Pt contents show an obvious aggregation of Pt nanoparticles.In addition,the average particle size of the Pt2/Ni@CN-doped sample was smaller than the other catalysts,which was 2.45 nm.The results of electrochemical tests showed that the Pt2/Nt@CN-doped sample possessed the lowest initial potential of electrocatalytic oxidation of ethanol and the highest peak current density of 250.58 mA mg-1,the lowest CO oxidation peak potential of-0.601 V and the highest Electrochemical active surface area of 59.03 m2g-1,the best catalytic stability.This indicates that Pt2/Nt@CN-doped has excellent electrocatalytic activity for ethanol.The results is attributed to the efficient electronic transport structure of the Pt2/Ni@CN-doped sample.This paper provides a promising method for enhancing the conductivity of electrode material.In order to design a highly sensitive ethanol detection catalyst,a platinum-doped Ni/C-N composite catalyst was prepared in a simple and eco-friendly method(one-pot synthesis).The structure and morphologies of the materials were characterized by high resolution transmission electron microscopy(HRTEM)and X-ray diffraction(XRD).The results show that nickel nanoparticles with an average size of about 16.8 nm were uniformly dispersed on the carbon subsrate,and the mass percentage of Pt in the catalyst is as low as 0.01%.The electrocatalysis and sensing properties of the catalysts on ethanol were studied by cyclic voltammetry and other electrochemical tests.In alkaline solution,the synthesized materials have good electrocatalytic activity for ethanol with high sensitivity(37.4?A m(mol/L)-1cm-1)and wide detection range(0.85-444 mmol/L),and has excellent selectivity in the presence of various electroactive substances.