Copper nanoparticles-decorated polyaniline-derived mesoporous carbon that can serve as noble metal-free electrocatalyst for the hydrazine oxidation reaction (HzOR) is synthesized via a facile synthetic route. The material exhibits excellent electrocatalytic activity toward HzOR with low overpotential and high current density. The material also remains stable during the electrocatalytic reaction for long time. Its good electrocatalytic performance makes this material a promising alternative to conventional noble metal-based catalysts (e.g., Pt) that are commonly used in HzOR-based fuel cells.
A mesostructured composite catalyst, Pt-SnO2 supported on graphitized mesoporous carbon (GMC), has been prepared and its electrochemical activity for methanol oxidation has been investigated. The materials were characterized by XRD, FESEM, TEM, EDX spectrum and N2 sorption techniques. Cyclic voltammetry, chronoamperometry and steady-state polarization tests were adopted to characterize the electro-catalytic activities of the materials for methanol oxidation. The results show that, the overall methanol electro-oxidation catalytic activity of the mesostructured composite catalyst, 20 wt.% PtSnO2 (1:1, mass ratio)/GMC, is obviously higher than that of 20 wt.% PtSnO2/C with commercial carbon black as support under the same loading amount of Pt-SnO2 catalysts, and is also much higher than that of commercial catalyst 20 wt.% Pt/C at half Pt using amount. 相似文献
Highly ordered meso-porous carbon, denoted CMK-3 was synthesized by using mesoporous silicates, SBA-15 as the starting templating materials. The ordered mesoporous carbon was loaded with platinum and platinum-ruthenium nanoparticles using alternative synthesis techniques. The metal loaded ordered mesoporous carbon powders were characterized by transmission electron microscopy (HRTEM), energy dispersive X-ray analysis (EDX), X-ray diffraction, and nitrogen adsorption isotherm experiments. Micrometer-scale and centimeter-scale electrodes containing the mesocarbon/nanometal electrocatalysts were tested for some typical fuel cell reactions. While the nanometal/mesocarbon catalysts have well-defined and uniform properties in the nanometer scale, they have mixed electrocatalytic performance. A synthesized Pt/mesocarbon electrocatalyst outperformed a commercial electrocatalyst for oxygen reduction on a gas-diffusion electrode. The Pt-Ru/mesocarbon electrocatalyst synthesized, however, was not as effective for methanol oxidation. 相似文献
Two carbon aerogels with different nanopore size distributions but both with high surface area, high nanoporous volume and
low bulk density have been compared as platinum support. The influence of the nanostructure of the carbon aerogel on the platinum
nanoparticle deposit was investigated. The platinum was deposited on the carbon by means of two different techniques, one
employing an anionic platinum precursor, the other using a cationic one. The porosity of the carbon aerogels was characterized
by combining N2-sorption and mercury porosimetry. The platinum deposit was characterized by transmission electron microscopy and rotating
disk electrode experimentation to measure the platinum active surface area and its activity towards oxygen reduction reaction
(ORR). The structural differences between the carbon aerogels did not yield any difference in platinum deposits in terms of
Pt-surface area and ORR activity. Interestingly, the ORR mass activity of the high Pt-surface area samples, obtained by the
cationic insertion technique, was several times lower than that of the samples obtained by the anionic technique. This observation
was attributed to the particle size effect, detrimental in the case of platinum particle size around 1 nm. 相似文献
Platinum–ruthenium alloy electrocatalysts, for methanol oxidation reaction, were prepared on carbons thermally treated in helium atmosphere or chemically functionalized in H2O2, or in HNO3 + H2SO4 or in HNO3 solutions. The functionalized carbon that is produced using acid solutions contains more surface oxygenated functional groups than carbon treated with H2O2 solution or HeTT. The XRD/HR-TEM analysis have showed the existence of a higher alloying degree for Pt–Ru electrocatalysts supported on functionalized carbon, which present superior electrocatalytic performance, assessed by cyclic voltammetry, chronoamperometry and electrochemical impedance spectroscopy, as compared to electrocatalysts on unfunctionalized carbon. It also was found that Pt–Ru alloy electrocatalysts on functionalized carbon improve the reaction rate compared to Pt–Ru on carbons treated with H2O2 solution and thermally. A mechanism is discussed, where oxygenated groups generated from acid functionalization of carbon and adsorbed on Pt–Ru electrocatalysts are considered to enhance the electrocatalytic activity of the methanol oxidation reaction. 相似文献
A simple approach for the synthesis of nanosized platinum particles supported on ordered mesoporous carbons (OMCs) was described. For the first time, we successfully used the positively charged poly-(diallydimethylammonium chloride, PDDA) to wrap OMCs and attached Pt nanoparticles (OMCs–PDDA/Pt) via electrostatic interaction. The obtained OMCs–PDDA/Pt nanocomposites were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM) and electrochemical methods. TEM images reveal that the Pt nanoparticles with an average size of ∼2.88 nm are uniformly dispersed on the surface of OMCs–PDDA. The electrocatalytic behavior of OMCs–PDDA/Pt modified glassy carbon (GC) electrode was investigated by cyclic voltammetry, current–time and chronoamperometry methods using hydrazine as a redox probe. The electrochemical results indicate that the OMCs–PDDA/Pt exhibit a good electrocatalytic activity toward the oxidation of hydrazine than that of OMCs/Pt. All these electrochemical measurements confirm the fact that the OMCs–PDDA/Pt nanocomposites may have applications in biological and environmental sensors. 相似文献
The effect of the inclusion of Mo, Nb and Ta in Pt and PtRu carbon supported anode electrocatalysts on CO tolerance in proton exchange membrane fuel cells (PEMFC) has been investigated by cyclic voltammetry and fuel cell tests. CO stripping voltammetry on binary PtxM/C (M: Mo, Nb, Ta) reveals partial oxidation of the CO adlayer at low potential, with PtMo (4:1)/C exhibiting the lowest value. At 80 °C, the operating temperature of the fuel cell, CO oxidation was observed at potentials close to 0 V versus the reversible hydrogen electrode (RHE). No significant difference for CO electro-oxidation at the lower potential limit, compared to PtRu/C, was observed for PtRuMy/C (M: Mo, Nb). Fuel cell tests demonstrated that while all the prepared catalysts exhibited enhanced performance compared to Pt/C, only the addition of a relatively small amount of Mo to PtRu results in an electrocatalyst with a higher activity, in the presence of carbon monoxide, to PtRu/C, the current catalyst of choice for PEM fuel cell applications. 相似文献