The Controable Synthesis Of Graphene Supported PtM And PdM Intermetallic And The Research Of Their Elactrocatalytic Performance

This paper prepared several noble metal metallic/graphene composites to improve theirelectrocatalytic activities of oxygen reduction and ethanol oxidation. It consisted of threeparts as follows:1. Graphene-PdxMy(M=Fe, Co) intermetallic catalysts were synthesised by thermaltreatment of intermetallic and then chemical leaching or dealloying. The best molar ratio ofGraphene-PdxFey is1/3, the activity of deallyed catalyst towards oxygen reduction reaction(ORR) was2times greater than not deallyed, the current density also is5times greater thancommercial Pt/C catalyst. The electrocatalytic activity of GR-Pd3Co is the highest, its currentdensity of catalytic oxygen is1.4times of GR-PdFe3.2. The GR-PtxMy(M=Fe, Co, and Cu) intermetallic catalyst with high catalytic activitywere prepared by thermal treatment. The influence of molar ratio and contents towards theelectrocatalytic activity of catalyst was studied. The catalytic activities for ORR are in theorder: GR-Pt3Fe>GR-Pt3Cu>GR-PtCo1.45>commercial Pt/C. Compared with commercialE-TEK Pt/C catalyst, the onset potential of GR-Pt3Fe towards ORR is positive shifted50mV,and the current density increases15times. The forward scan oxidation peak of ethanol onGR-Pt3Fe is negative shifted27mV than commercial Pt/C catalyst, the peak current densityincreases4times.3. The three-dimensional Pt dendrites supported on GR(3D-Pt/GR) were prepared by insitu decomposition reaction of formic acid. The3D-Pt/GR composites were characterized byscanning electron micrographs, X-ray diffraction, and Fourier transform infrared spectroscopy.The results showed that the Pt nanoparticles with dendrites structure were well-dispersed onthe surface of GR, and the strong interaction between the Pt and C can change theelectrocatalytic activity of the catalyst. Cyclic voltammetry and rotating disk electrode testresults showed that the electrocatalytic activity for oxygen reduction reaction of3D-Pt/GRcatalyst is5times higher than commercial Pt/C catalyst. However, the electrocatalytic activityfor ethanol oxidation of3D-Pt/GR catalyst decreases to only half of the Pt/C catalyst.