Noble metal

About: Noble metal is a research topic. Over the lifetime, 15113 publications have been published within this topic receiving 337947 citations.

In situ Synthesis of Metal Nanoparticle Embedded Free Standing Multifunctional PDMS Films.

Abstract: We demonstrate a simple one-step method for synthesizing noble metal nanoparticle embedded free standing polydimethylsiloxane (PDMS) composite films. The process involves preparing a homogenous mixture of metal salt (silver, gold and platinum), silicone elastomer and the curing agent (hardener) followed by curing. During the curing process, the hardener crosslinks the elastomer and simultaneously reduces the metal salt to form nanoparticles. This in situ method avoids the use of any external reducing agent/stabilizing agent and leads to a uniform distribution of nanoparticles in the PDMS matrix. The films were characterized using UV-Vis spectroscopy, transmission electron microscopy and X-ray photoemission spectroscopy. The nanoparticle-PDMS films have a higher Young's modulus than pure PDMS films and also show enhanced antibacterial properties. The metal nanoparticle-PDMS films could be used for a number of applications such as for catalysis, optical and biomedical devices and gas separation membranes.

Electrocatalytic H2 production from seawater over Co, N-codoped nanocarbons

Abstract: One of the main barriers blocking sustainable hydrogen production is the use of expensive platinum-based catalysts to produce hydrogen from water. Herein we report the cost-effective synthesis of catalytically active, nitrogen-doped, cobalt-encased carbon nanotubes using inexpensive starting materials—urea and cobalt chloride hexahydrate (CoCl2·6H2O). Moreover, we show that the as-obtained nanocarbon material exhibits a remarkable electrocatalytic activity toward the hydrogen evolution reaction (HER); and thus it can be deemed as a potential alternative to noble metal HER catalysts. In particular, the urea-derived carbon nanotubes synthesized at 900 °C (denoted as U-CNT-900) show a superior catalytic activity for HER with low overpotential and high current density in our study. Notably also, U-CNT-900 has the ability to operate stably at all pH values (pH 0–14), and even in buffered seawater (pH 7). The possible synergistic effects between carbon-coated cobalt nanoparticles and the nitrogen dopants can be proposed to account for the HER catalytic activity of U-CNT-900. Given the high natural abundance, ease of synthesis, and high catalytic activity and durability in seawater, this U-CNT-900 material is promising for hydrogen production from water in industrial applications.

Influence of iridium oxide loadings on the performance of PEM water electrolysis cells: Part I–Pure IrO2-based anodes

Abstract: The influence of iridium oxide loadings at the anode of PEM water electrolysis cells on the overall electrochemical performance was studied using cyclic voltamperometry and electrochemical impedance spectroscopy, and by measuring polarization curves at 80 °C. Membrane electrode assemblies with reduced metal loadings (0.25 mg cm−2 of Pt at the cathode and 0.5 mg cm−2 of IrO2 at the anode) were prepared using the decal method. A typical cell voltage of 1.72 V was recorded using a 25 cm2 cell with a Nafion® 115 membrane at a current density of 1 A cm−2 (at 80 °C and atmospheric pressure). Performances measured with such reduced noble metal loadings are similar to those obtained with conventional loadings of several mg cm−2.

A nonmetal catalyst for molecular hydrogen activation with comparable catalytic hydrogenation capability to noble metal catalyst.

Abstract: Fullerene can activate molecular hydrogen and is a novel nonmetal hydrogenation catalyst. The hydrogenation of aromatic nitro compounds to amino aromatics is achieved on this catalyst with high conversion and selectivity under 1 atmospheric pressure of H2 and light irradiation at room temperature or under conditions of 120−160 °C and 4−5 MPa H2 pressure without light irradiation, which is comparable to the case with a noble metal catalyst.