Controllable Deposition of Platinum Nanoparticles on Graphene As an Electrocatalyst for Direct Methanol Fuel Cells

Abstract

Platinum nanoparticles (Pt NPs) with uniform size and high dispersion have been successfully assembled on poly(diallyldimethylammonium chloride) functionalized graphene oxide via a sodium borohydride reduction process. The loading concentration of Pt NPs on graphene can be adjusted in the range of 18À78 wt %. The obtained Pt/graphene nanocomposites are characterized by transmission electron microscopy, high resolution transmission electron microscopy, energy dispersive spectrometry, X-ray diffraction, and thermogravimetric analysis. The results show that the Pt NPs with sizes of approximate 4.6 nm uniformly disperse on graphene surface for all Pt loading densities. Electrochemical studies reveal that the Pt/graphene nanocomposites with electrochemically active surface area of 141.6 m 2 /g show excellent electrocatalytic activity toward methanol oxidation and oxygen reduction. The present method is promising for the synthesis of high performance catalysts for fuel cells, gas phase catalysis, and sensors.

In situ thermolysis of Pt-carbonyl complex to form supported clean Pt nanoclusters with enhanced catalytic performance

“…It is noted that a sharp diffraction peak appears at 10.8°f or pure GO, which is ascribed to the (002) plane of the graphene sheets of a few layers. After the formation of supported nanocatalysts, a new diffraction peak appeared at about 25°, implying the existence of stacking structures of rGO [32]. Two characteristic diffraction peaks of (111) and (200) (JCPDS card 01-087-0642) are very broad, implying very small sizes of the sample.…”

Graphene-based hybrid materials and their applications in energy storage and conversion

“…The hybrid electrode shows a much higher catalytic activity, better stability and tolerance toward CO. The maximum power density of graphene/ Pt catalyst is 260 mW cm 2 at 540 mV, which is higher than that of the commercial Pt/C catalyst (139 mW cm 2 at 540 mV) [62]. PtRu/graphene catalyst was prepared and compared with PtRu/MWCNTs catalysts in the application in direct methanol fuel cells, in which the current value of PtRu/ graphene catalyst is about 2.5 times higher than that of the PtRu/MWCNTs catalyst.…”

One Pot Synthesis of Pt/Graphene Composite Using Polyamidoamine/Chitosan as a Template and Its Electrocatalysis for Methanol Oxidation

“…The higher ECSA of Pt/GNs (PAMAM) and Pt/GNs (CS) are obviously related to the unique morphology and uniform distribution of Pt nanoparticles, which is helpful to improve their catalytic performance [37]. and their standard deviation is less than 3%; b The onset potential is defined as the potential at which 10% of the current value at the peak potential was reached in this work [34].…”

“…It is observed that the onset potential value for Pt/GNs (CS) and Pt/GNs (PAMAM) is 0.36 and 0.35 V, respectively, which is lower than that for Pt/GNs (0.40 V) and Pt/C (0.45 V) (Table 1). Lower onset potential may contribute to superior electro-catalytic activity for methanol oxidation [37,45]. It is reported that the functional-modified graphene is in favor of inhibiting the irreversible aggregation process of Pt/graphene composites [46].…”

“…Powder X-ray diffraction (XRD) patterns of Pt/GNs, Pt/GNs (CS), and Pt/GNs (PAMAM) are shown in Figure 3A. The diffraction peaks at 40.0 • , 46.5 • , 67.8 • , 81.6 • , and 86.2 • (2θ value) can be assigned to (111), (200), (220), (311), and (222) crystalline planes of Pt (0) fcc lattice, respectively [37], which further indicates good crystallinity and zero-valent state of Pt in the obtained three composites. The diffraction peak for Pt (220) is used to estimate the size of Pt nanoparticles with the Scherrer Equation (1) [30,37].…”