Nanowire of platinum

Irradiation by ionizing radiation able to penetrate into a zeolite material exchanged by metal ions allows to generate metal atoms and clusters in situ in the cavities.The observation of irradiated faujasite (Na-Y zeolite) by optical absorption spectroscopy at increasing doses and at low silver content demonstrates the formation of two bands at 265 and 305 nm which have been assigned to the charged trimer Agj ". Then, the ESR observation after a dehydration step indicates the reduction of this species into Agj . Irradiation of HjPtClg solution included in mesoporous channels of molecular sieves induces nanowires of platinum. ... 

Chen, J.Y., Herricks, T., Geissler, M. and Xia, Y.N. (2004) Single-crystal nanowires of platinum can be synthesized by controlling the reaction rate of a polyol process. Journal of the American Chemical Society, 126,10854. 

Saha, M. S., Li, R., Cai, M., and Sun, X. High electrocatalytic activity of platinum nanoparticles on Sn02 nanowire-based electrodes. Electrochemical and Solid-State Letters 2007 10 B130-B133. 

Consequently, the contamination danger can be minimized. Furthermore, isotope dilution analysis with LA-ICP-MS can be used as a microlocal analytical technique for multi-element determination in thin layers or nanowires of high purity platinum and palladium nanoclusters on DNA. LA-ICP-MS allows microlocal analysis for studying the elemental distribution in layered systems and bulk material. 

A number of other types of processes that can be considered a form of self-assembly at surfaces are just beginning to appear. The selective oxidation of silicon, followed by etching of the silicon dioxide, as a route to silicon nanowires is an example172 the galvanic deposition of platinum on selenium nanostructures, followed by removal of the selenium, to make nanowalls with complex shapes is a second173,174. 

Mayers, B., Jiang, X., Sunderland, D., Cattle, B. Xia, Y. Hollow nanostructures of platinum with controllable dimensions can be synthesized by templating against selenium nanowires and colloids. 

Fukuoka, A., Higashimoto, N., Sakamoto, Y., Sasaki, M., Sugimoto, N., Inagaki, S., Fukushima, Y. and Ichikawa, M. Ship-in-bottle synthesis and catalytic performances of platinum carbonyl clusters, nanowires, and nanoparticles in microporous and mesoporous materials, Catal. Today, 2001, 66, 23-31. 

Besides, it has been shown that palladium is promising for direct alcohol fuel cells applications as it is very active for ethanol electro-oxidation in basic media and that its electroactivity is even higher than that of platinum. Recently, Pd nanoballs and nanowires synthesized by radiolysis in hexagonal mesophases have shown an important elec-trocatalytic activity for ethanol electro-oxidation. ... 

F.-J. Liu, L.-M. Huang, T.-C. Wen, A. Gopalan, and J.-S. Hung, Interfacial synthesis of platinum loaded polyaniline nanowires in poly(styrene sulfonic acid). Mater. Lett., 61,4400 4405 (2007). 

F.J. Liu, L.M. Huang, T.C. Wen, and A. Gopalan, Large-area network of polyaniUne nanowires supported platinum nanocatalysts for methanol oxidation, Synth. Met., 157, 651-658 (2007). 

This selected brief review will be focused on the research and development progress on ORR kinetics. The origin of the problem related with the low ORR activity of platinum will be discussed, followed by a review of recent progress in making more active, more durable platinum-based ORR catalysts. These include platinum alloy catalysts, platinum monolayer catalysts, platinum nanowire and nanotube catalysts, and the more recent shape- and facet-controlled platinum-alloy nanocrystal catalysts. The progress in the mechanistic understanding on the correlation between the activity and the electronic and structural properties of surface platinum atoms will be reviewed as well. The future direction of the research on platinum-based catalysts for PEM fuel cell apphcation will be proposed. 

Liang ZX, Zhao TS. New DMFC anode structure consisting of platinum nanowires deposited into a Nafion membrane. J Phys Chem C 2007 111 8128-34. 

This chapter reviewed various one-dimensional catalyst supports including carbon nanotubes, carbon nanofibers and metal oxide nanowires as replacement of carbon black support to increase the utilization of platinum and enhance the durability of electrodes in fuel cells. 

Later investigations aimed to perfect the technique of molecular combing through improvements such as combing on unmodified hydrophilic surfaces/ inside microchannels (Fig. 16.1e)/ and, together with soft lithography, in precisely defined arrays (Fig. 16.1f. Such precise placement of DNA has also become important for microelectronics applications, since chemical methods have been devised to transform combed DNA to nanowires of various materials, such as copper and platinum for a review, see Stoltenberg and Woolley. ... 

Contreras AM, Grunes J, Yan XM, Liddle A, Somorjai GA (2005) Fabrication of platinum nanoparticles and nanowires by electron beam lithography (EBL) and nanoimprint lithography (NIL) comparison of ethylene hydrogenation kinetics. Catal Lett 100 115-124... 

Yan XM, Kwon S, Contreras AM, Koebel MM, Bokor J, Somoijai GA (2005) Fabrication of dense arrays of platinum nanowires on silica, alumina, zirconia and ceria surfaces as 2-D model catalysts. Catal Lett 105 127-132... 

Peng Z, You H, Yang H (2010) Composition-dependent formation of platinum silver nanowires. ACS Nano 4 1501... 

J. Li, R. Yuan, Y. Chai, T. Zhang, X. Che, Direct electrocatal54ic reduction of hydrogen peroxide at a glassy carbon electrode modified with polypyrrole nanowires and platinum hollow nanospheres, Microchim Acta 171 (2010) 125-131. 

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