| Summary: | 碩士 === 國立高雄應用科技大學 === 化學工程與材料工程系 === 100 === Using defective graphene nanpsheets (GNS), single-wall carbon nanotubes (SWCNT) and graphite nanofibers (GNF) as different supports for Pd3Pt1 catalysts toward acidic oxygen reduction reactions (ORRs) has been investigated. Herein, the GNS-supported Pd3Pt1 nanocomposites (Pd3Pt1/GNS), the SWCNT-supported Pd3Pt1 nanocomposites (Pd3Pt1/SWCNT), the GNF-supported Pd3Pt1 nanocomposite (Pd3Pt1/GNF) were successfully prepared by self-regulated surfactant. Based on measurements supported by transmission electron microscopy, the average sizes of these alloy particles on GNS, SWCNT, and CNF were 4nm, 3nm, and 3.7nm, respectively. This indicates that the substrate did not significantly influence the nanoparticle sizes during the synthesis period. As identification by Raman spectrum, the intensity ratio of D-bond to G-bond peak (R) increased from 1.01 to 1.23 after the Pd3Pt1 catalysts attaching to GNS. Simultaneously, the increases of 0.02 to 0.61 and 1.08 to 1.12 were in the cases of SWCNT and GNF, respectively. This could be due to partial destruction of the carbon rings during synthesis process, especially for SWCNT.
The ORR activities of these three Pd3Pt1/ carbon support catalysts were investigated in a acidic solution (0.5M H2SO4) at 0.65V (vs. SCE), and the parameters were determined by the rotating ring-disk electrode (RRDE) technique. The data shows the mass activity (jm) Pd3Pt1/GNS, Pd3Pt1/SWCNT, Pd3Pt1/CNF, commercial catalyst E-TEK (Pt/C) were 6.23×10-3 mAμg-1Pt, 4.33×10-3 mAμg-1Pt, 2.19×10-3 mAμg-1Pt, and 1.71×10-3mAμg-1Pt, respectively. Among these catalysts, the Pd3Pt1/GNS has highest activity in mass.
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