Topic
Platinum
About: Platinum is a research topic. Over the lifetime, 49675 publications have been published within this topic receiving 1150035 citations. The topic is also known as: Pt & element 78.
Papers published on a yearly basis
Papers
More filters
••
TL;DR: In this article, carbon nanotube (CNT)-supported Pt catalysts have been prepared by impregnation and reduction-precipitation method using chloroplatinic acid as metal precursor.
Abstract: Carbon nanotube (CNT)-supported Pt catalysts have been prepared by impregnation and reduction–precipitation method using chloroplatinic acid as metal precursor. The structure of the catalysts has been characterised using TEM, BET and XPS. The catalytic performance for nitrobenzene hydrogenation was evaluated under atmospheric pressure and ambient temperature. The results show that the catalysts, both of low and higher Pt loading, show high activity for nitrobenzene directly hydrogenating to aniline under mild conditions. The highly dispersed Pt and mesoporosity structure of acid-oxidized CNT-supported Pt catalyst are responsible for the extraordinary activity.
179 citations
••
TL;DR: It is proposed that the potential formed in the hetero-interface stabilizes hydrogen atoms rather than interstitials in the Pd core and Pt shells, suggesting that metal nanoparticles a few nanometers in size can act as a new type of hydrogen storage medium.
Abstract: The hydrogen storage properties of metal nanoparticles change with particle size. For example, in a palladium-hydrogen system, the hydrogen solubility and equilibrium pressure for the formation of palladium hydride decrease with a decrease in the particle size, whereas hydrogen solubility in nanoparticles of platinum, in which hydrogen cannot be stored in the bulk state, increases. Systematic studies of hydrogen storage in Pd and Pt nanoparticles have clarified the origins of these nanosize effects. We found a novel hydrogen absorption site in the hetero-interface that forms between the Pd core and Pt shell of the Pd/Pt core/shell-type bimetallic nanoparticles. It is proposed that the potential formed in the hetero-interface stabilizes hydrogen atoms rather than interstitials in the Pd core and Pt shells. These results suggest that metal nanoparticles a few nanometers in size can act as a new type of hydrogen storage medium. Based on knowledge of the nanosize effects, we discuss how hydrogen storage media can be designed for improvement of the conditions of hydrogen storage.
179 citations
••
TL;DR: In this paper, small palladium and platinum clusters have been synthetized within a purely hydrocarbon polymer matrix using ring-opening metathesis polymerisation of norbornene-derived organometallic complexes, using W or Mo alkylidene initiators.
Abstract: Small palladium and platinum clusters have been synthetized within a purely hydrocarbon polymer matrix. The procedure consists of ring-opening metathesis polymerisation of norbornene-derived organometallic complexes, Pd(Cp N )(PA) and Pt(Cp N )Me 3 (Cp N = endo-2-(cyclopentadienylmethyl)norbon-5-ene and PA = η 3 -1-phenylallyl), using W or Mo alkylidene initiators, followed by static casting of films and subsequent reduction of the organometallic complexes under mild conditions using molecular hydrogen
179 citations
••
TL;DR: The chemistry of binuclear palladium(II) and platinum (II) complexes has been reviewed in this paper, which deals with complexes derived from various classes of ligands and covers various aspects, viz. synthesis, spectroscopic and structural features and chemical reactivity of these complexes.
179 citations
••
TL;DR: In this paper, three bimetallic PtSn/C catalysts have been prepared by successive impregnation of pregraphitized carbon black with an aqueous solutions of hexachloroplatinic acid and tin(II) chloride.
Abstract: Three bimetallic PtSn/C catalysts have been prepared by successive impregnation of pregraphitized carbon black with an aqueous solutions of hexachloroplatinic acid and tin(II) chloride. One monometallic Pt/C sample was also prepared and studied for comparison. All catalysts were characterized by hydrogen and carbon monoxide chemisorption at room temperature and X-ray photoelectron spectroscopy and their behaviour in the gas phase hydrogenation of crotonaldehyde, at atmospheric pressure, determined. The amount of surface platinum is greatly reduced by the addition of tin, as deduced from chemisorption measurements and XPS. Both Pt0 and PtII are detected by XPS in the fresh bimetallic catalysts; after reduction in flowing hydrogen at 623 K platinum is completely reduced to the metallic state and, although a high proportion of tin remains in an oxidized state, a relatively important amount is reduced to Sn0, this allowing the possibility of PtSn alloys formation. The catalytic activity in the gas phase hydrogenation of crotonaldehyde is greatly improved by the presence of tin, in spite of the fact that the amount of surface platinum is reduced. Tin has also a very important effect on the selectivity towards the hydrogenation of the CO bond, increasing the production of crotyl alcohol in respect to the hydrogenation of the CC bond that would lead to the production of butyraldehyde. The observed results are explained on the basis of a promoting effect of oxidized tin species for the hydrogenation of the CO group, whereas the formation of a PtSn alloy or the dilution of surface platinum by metallic tin would hinder the hydrogenation of the olefinic CC bond.
179 citations