Carbon-supported Bimetallic Nanoparticles Research Articles

PtNi and PtMo nanoparticles as efficient catalysts using TEA-PS.BF4 ionic liquid as electrolyte towards HER

Carbon-supported bimetallic nanoparticles, PtNi/C and PtMo/C, were synthesized using the borohydride reduction method and were tested as cathode in the hydrogen evolution reaction (HER) employing acid aqueous solution of 3-triethylammonium-propanesulfonic acid tetrafluoroborate (TEA-PS.BF4) ionic liquid as the electrolyte. For comparison a commercial carbon-supported Pt nanoparticles (Pt/C) has been tested. The morphology, composition and structure of the carbon-supported nanoparticles were characterized by EDX, XRD, and TEM. The results obtained by chronoamperometry, Tafel plots and electrochemical impedance spectroscopy (EIS) exhibited an excellent catalytic effect and the same kinetics mechanism for all carbon-supported nanoparticles in HER studied. Results of Tafel analysis showed that the HER rate determining step is the Volmer–Heyrovsky mechanism. In the temperature range 25–80 °C, the PtNi/C and PtMo/C cathodes presented lower activation energy and higher current density than system using the Pt/C cathode. The PtMo/C cathode improves charge transfer kinetics and hydrogen adsorption, while the PtNi/C cathode facilitates the desorption step. These results demonstrate that the carbon-supported bimetallic nanoparticles PtNi/C and PtMo/C are responsible for increasing the catalytic performances of the HER when TEA-PS.BF4 aqueous solution is employed as electrolyte.

Sustainable application of pecan nutshell waste: Greener synthesis of Pd-based nanocatalysts for electro-oxidation of methanol

Palladium-based electrocatalysts are widely used in alkaline direct alcohol fuel cells. The synthesis and characterization of carbon-supported bimetallic nanoparticles (NP) of AuPd and AgPd is described using pecan nutshell extract (Carya illinoinensis) which serves as both, reducing and the stabilizing agent. This environmentally friendly route generates bimetallic NP for a wide range of applications, including electrocatalysis; since particularly AuPd NP proved to be a potentially suitable electrode material for alkaline direct methanol fuel cells. The electrocatalytic activity of these nanomaterials was comparable to commercially available Pd/C 1% in the electro-oxidation of methanol in alkaline media.

Synthesis and Characterization of Carbon-supported Bimetallic Nanoparticles for the Oxygen Reduction Reaction

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Pt–Fe cathode catalysts to improve the oxygen reduction reaction and methanol tolerance in direct methanol fuel cells

High surface area carbon-supported Pt and bimetallic Pt–Fe catalysts are investigated for the oxygen electro-reduction reaction (ORR) in low-temperature direct methanol fuel cells (60 °C). The electrocatalysts are prepared using a combination of colloidal and incipient wetness methods allowing the synthesis of carbon-supported bimetallic nanoparticles with a particle size of about 2–3 nm. These materials are studied in terms of structure, morphology and composition using X-ray diffraction, X-ray fluorescence and transmission electron microscopy techniques. The electrocatalytic behaviour of these catalysts for ORR is investigated by employing the rotating disc technique. An enhancement of the ORR is observed with the bimetallic Pt–Fe catalyst in the oxygen-saturated electrolyte solution, with and without methanol.

Preparation of Carbon‐Supported PtNi Nanoparticles via the Single Source Molecular Precursor Approach.

AbstractFor Abstract see ChemInform Abstract in Full Text.

Preparation of Carbon-Supported PtNi Nanoparticles via the Single Source Molecular Precursor Approach

Carbon-supported PtNi nanoparticles have been prepared from the thermolysis of a single source precursor The single source precursor is highly stable under ambient conditions, allowing easy materials handling and storage. The carbon-supported PtNi nanoparticles had a mean diameter of 8.3 nm and were obtained by a two-stage process involving the ballmilling of carbon and the precursor and the thermal degradation of the homogenized mixture at 550°C in a flowing gas mixture. The carbon-supported bimetallic nanoparticles were characterized by powder X-ray diffraction scanning electron microscopy-energy-dispersive X-ray, and transmission electron microscopy. The electro-oxidation of methanol over this catalyst was investigated and benchmarked against a commercial E-TEK Pt/C catalyst. The catalytic activity was higher for this homemade catalyst, which also displayed improved resistance to catalyst deactivation. © 2004 The Electrochemical Society. All rights reserved.