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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.


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Journal ArticleDOI
TL;DR: The MoSoy catalyst as mentioned in this paper is composed of a catalytic β-Mo2C phase and an acid-proof γ-Mo 2N phase, and is highly durable in a corrosive acidic solution over a period exceeding 500 hours.
Abstract: The production of hydrogen from water electrolysis calls for an efficient non-precious-metal catalyst to make the process economically viable because of the high cost and the limited supply of the currently used platinum catalysts. Here we present such a catalyst made from earth-abundant molybdenum and common, humble soybeans (MoSoy). This catalyst, composed of a catalytic β-Mo2C phase and an acid-proof γ-Mo2N phase, drives the hydrogen evolution reaction (HER) with low overpotentials, and is highly durable in a corrosive acidic solution over a period exceeding 500 hours. When supported on graphene sheets, the MoSoy catalyst exhibits very fast charge transfer kinetics, and its performance rivals that of noble-metal catalysts such as Pt for hydrogen production. These findings prove that the soybean (as well as other high-protein biomass) is a useful material for the generation of catalysts incorporating an abundant transition metal, thereby challenging the exclusivity of platinum catalysts in the hydrogen economy.

318 citations

Journal ArticleDOI
03 Feb 2000-Langmuir
TL;DR: In this paper, poly(amidoamine) dendrimers were used to obtain stable nanoparticles of gold, platinum, and silver by reduction of their metal salts with NaBH4.
Abstract: Nanoparticles of gold, platinum, and silver were prepared by reduction of their metal salts with NaBH4 in the presence of poly(amidoamine) dendrimers. The dendrimers used were generation 3, 4, and 5 having surface amino group (G3, G4, and G5) as well as generation 3.5, 4.5, and 5.5 having surface carboxyl group (G3.5, G4.5, and G5.5). The metal nanoparticles obtained were characterized by UV−vis spectroscopy and transmission electron microscopy. By using G3−G5, gold nanoparticles in the 1.5−4.0 nm size regime were obtained where their size decreased with increasing concentration of the dendrimers as well as the generation of the dendrimers. Similarly, platinum nanoparticles with a diameter of 2.4−3.0 nm were obtained, and their size was insensitive against the concentration as well as the generation of G3−G5. In the case of silver nanoparticles, very small silver particles using G3.5−G5.5 were obtained. In addition, the dendrimer concentration required for obtaining stable nanoparticles was found to be de...

318 citations

Journal ArticleDOI
TL;DR: In this paper, a WO3-based gas sensor has been fabricated by reactive reactive rf sputtering on glass substrates, where Palladium (Pd), platinum (Pt), gold (Au), noble metals (100-600 A), and Al layers (1500 A) were sputtered on top of them as upper electrodes for sensor output.
Abstract: WO3-based gas sensor devices have been fabricated by reactive rf sputtering on glass substrates. Palladium (Pd), platinum (Pt), gold (Au) noble metals (100–600 A) were evaporated as activator layers onto WO3 thin films and Al layers (1500 A) were sputtered on top of them as upper electrodes for sensor output. The described sensing element was found to possess excellent sensitivity towards NO and NO2 gases, at low temperatures (100–300°C). The optimum operating temperature was 150 and 200°C for Pt, Pd and Au, respectively. The resistance of the thin-film gas sensor increases reversibly in the presence of low concentrations of NO (0–440 ppm) and NO2 (0–10 ppm) gases in air. The activator layers have an promotional effect on the speed of response to NOx at low temperatures and on selectivity enhanced with respect to other reducing gases (CO, CH4, H2, SO2, H2S, NH3). The temperature dependence of response and recovery times has been examined. The influence of the thickness of the noble metals on NOx gases sensitivity has been investigated. The NO and NO2 gases calibration curves have been recorded for the optimum performances of each fabricated sensor-device.

317 citations

Journal ArticleDOI
04 Oct 2002-Science
TL;DR: Platinum-carbene complexes are reported that catalyze the hydrosilylation reaction of alkenes with remarkable efficiency and exquisite selectivity and avoid the formation of platinum colloids.
Abstract: The hydrosilylation reaction enables the production of silicon polymers. Platinum-carbene complexes are reported that catalyze the hydrosilylation reaction of alkenes with remarkable efficiency and exquisite selectivity and avoid the formation of platinum colloids. By-products, typically encountered with previous catalytic systems, are suppressed with these platinum derivatives.

317 citations

Journal ArticleDOI
TL;DR: In this paper, an electrochemical flow cell system connected to an inductively coupled plasma mass spectrometer (ICP-MS) capable of online quantification of even small traces of dissolved elements in solution is investigated.
Abstract: Platinum is one of the most important electrode materials for continuous electrochemical energy conversion due to its high activity and stability. The resistance of this scarce material towards dissolution is however limited under the harsh operational conditions that can occur in fuel cells or other energy conversion devices. In order to improve the understanding of dissolution of platinum, we therefore investigate this issue with an electrochemical flow cell system connected to an inductively coupled plasma mass spectrometer (ICP-MS) capable of online quantification of even small traces of dissolved elements in solution. The electrochemical data combined with the downstream analytics are used to evaluate the influence of various operational parameters on the dissolution processes in acidic electrolytes at room temperature. Platinum dissolution is a transient process, occurring during both positive- and negative-going sweeps over potentials of ca. 1.1 VRHE and depending strongly on the structure and chemistry of the formed oxide. The amount of anodically dissolved platinum is thereby strongly related to the number of low-coordinated surface sites, whereas cathodic dissolution depends on the amount of oxide formed and the timescale. Thus, a tentative mechanism for Pt dissolution is suggested based on a place exchange of oxygen atoms from surface to sub-surface positions.

317 citations


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Performance
Metrics
No. of papers in the topic in previous years
YearPapers
20231,041
20221,789
2021867
20201,180
20191,408
20181,449