Carbon-supported platinum-based nanoparticles

Catalytic Dehydrogenation of Decalin and Methylcyclohexane over Carbon-Supported Platinum-Based Nanoparticles under Superheated Liquid-Film Conditions... 

In the present article, the size and the loading efficiency of metal particles were investigated by changing the preparation method of carbon-supported platinum catalysts. First, the effect of acid/base treatment on carbon blacks supports on the preparation and electroactivity of platinum catalysts. Secondly, binary carbon-supported platinum (Pt) nanoparticles were prepared using two types of carbon materials such as carbon blacks (CBs) and graphite nanofibers (GNFs) to check the influence of carbon supports on the electroactivity of catalyst electrodes. Lastly, plasma treatment or oxyfluorination treatment effects of carbon supports on the nano structure as well as the electroactivity of the carbon supported platinum catalysts for DMFCs were studied. 

Platinum-based nanoparticles (e.g., Pt [1-15], Pt-Re [10,15], and Pt-W [5,6,15]) supported on granular activated carbon (KOH-activation, BET specific surface area 3100 m2/g, pore volume 1.78 cm3/g, average particle size 13 pm, average pore size 2.0 nm, Kansai Netsukagaku Co. Ltd. [32]) were mainly used as the dehydrogenation catalysts in the present study. 

These pioneering results on smooth platinum obtained by EMIRS were confirmed by the new IR Reflectance Spectroscopy developed by Pons et al. (SNIFTIRS) and Weaver et al. (SPAIRS), able to observe intermediate species produced on carbon (e.g. Vulcan XC-72) supported Pt-based nanoparticles. 

Park, S., Y. Xie, and M.J. Weaver, Electrocatalytic pathways on carbon-supported platinum nanoparticles Comparison of particle-size-dependent rates of methanol, formic acid und formaldehyde electrooxidation. Langmuir, 2002. 18(15) pp. 5792-5798 Vinodgopal, K., M. Haria, D. Meisel, and P. Kamat, Fullerene-based carbon nanostructures for methanol oxidation. Nano Letters, 2004. 4(3) pp. 415 18 Sun, N.X. and K. Lu, Physical Review B, 1997. 54 pp. 6058... 

Platinum based catalysts supported on carbon black allowed to significantly increase the power density per electrode area as compared to platinum black type catalysts. The pore system of the support material allows to increase the platinum dispersion and partially prevents migration and the agglomeration of nanoparticles thus leading to a higher specific surface area. 

The high cost of platinum means that the car industry strives to reduce the amount of catalyst required in a PEM fuel cell. Current strategies focus on the use of PtM nanoparticles (M = another ri-block metal), nanoparticles with a PtM core encased in Pt atoms, and thin Pt films dispersed on nanostructured supports. Iron-based catalysts would be much cheaper, but their performance is usually poor. A promising advance (still at the research stage) is in the application of microporous carbon-sup-ported iron-based catalysts in which the iron cations are thought to be coordinated in Fe(phen)2p sites, the phenanthroline-units being incorporated into graphitic sheets. ... 

Nanofibre for use in proton exchange membrane fuel cells has been a focus of research during the last 5 years. These fuel cells have the potential for high thermodynamic efficiency and almost zero emissions, but are currently hindered by high cost of the platinum-based catalyst and low durability. Carbon nanofibre webs as a supporting medium for platinum nanoparticles have been employed [46]. 

State-of-the-art catalyst in low and intermediate temperature polymer electrolyte membrane fuel cells (PEMFC) is a powdered material consisting of platinum nanoparticles between 1 and 5nm in size that are supported—preferably in high dispersion—on a carbon-based support. 

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