scispace - formally typeset
Search or ask a question
Topic

Noble metal

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


Papers
More filters
Journal ArticleDOI
TL;DR: Nanocrystalline gold compounds have been the subject of intense research and have found far-reaching applications in areas such as catalysis, sensors, molecular electronics, or as bioconjugate probes for amplification tags in gene analysis, antibody or antigen detection, DNA sequencing, or gene mapping.
Abstract: Bulk gold is a noble metal and unlike its lighter congeners of Group 11, copper and silver, was for a long time not considered important in catalysis and surface science in general. Although it was known that atomic gold in the gas phase can be very reactive, it was not until 1987 that the interest in gold nanostructures was really awakened through the report by Haruta et al. on CO oxidation on supported gold catalysts such as Au/TiO2 or Au/Fe2O3 at low temperatures.[1] Since then nanocrystalline gold compounds have been the subject of intense research and have found far-reaching applications in areas such as catalysis, sensors, molecular electronics, or as bioconjugate probes for amplification tags in gene analysis, antibody or antigen detection, DNA sequencing, or gene mapping.[1, 2] For example, Wang et al. recently succeeded in attaching 1.4 nm gold clusters to the sphere of the cowpea mosaic virus (CPMV) of a diameter of 30 nm (Figure 1).[3] While most studies have so far concentrated on pure gold nanoclusters of different structure and size, the recent discovery of the extremely stable mixed icosahedral gold clusters W@Au12 and Mo@Au12 (Figure 2A) by Wang and coworkers[4]—as predicted earlier by theoretical studies by Pyykk; and Runeberg[5]—opens up the field to new nanosized gold materials, in which the central atom “impurity” plays a vital role in fine-tuning electronic properties.

223 citations

Journal ArticleDOI
TL;DR: In this article, the degradation of oxalic acid has been studied in aqueous solution photocatalyzed by band-gap-irradiated TiO2, modified with nanosized platinum or silver particles.
Abstract: The commercially available TiO2-catalyst (Degussa P25) was modified with nanosized platinum and silver particles by the photoreduction method to obtain different noble metal loading (0.5 and 1 wt.%). The characterization of the synthesized catalysts was carried out by the BET method, XPS, TEM and the adsorption of the model pollutant. The degradation of oxalic acid has been studied in aqueous solution photocatalyzed by band-gap-irradiated TiO2, modified with nanosized platinum or silver particles. The photocatalytic activity of TiO2, modified with noble metal, is approximately double that of the semiconducting support. The adsorption properties of the catalysts, as well as the noble metal content on the surface of the support, influence the efficiency of the photocatalytic process. The reaction rate of photocatalytic degradation of the oxalic acid follows a zero kinetic order according to the Langmuir–Hinshelwood model. The increase of the quantum yield of the photodestruction reaction of the studied model pollutant is due to the formation of Schottky barriers on the metal–semiconductor interface, which serve as efficient electron traps, preventing the electron–hole recombination.

222 citations

Patent
19 Nov 1990
TL;DR: In this article, an alloy of at least one noble metal of group VIII of the Periodic Table and a metal capable of alloying with the group VIII noble metal was used for producing an alcohol and/or a carboxylic acid ester.
Abstract: Catalyst composition comprising an alloy of at least one noble metal of group VIII of the Periodic Table and at least one metal capable of alloying with the group VIII noble metal, admixed with a component comprising at least one of the metals rhenium, tungsten or molybdenum, used for producing an alcohol and/or a carboxylic acid ester by reacting hydrogen with a carboxylic acid or anhydride thereof.

222 citations

Journal ArticleDOI
TL;DR: In this article, the resistivity and magnetic susceptibility measurements on sintered Bi4Sr3Ca2Cu4O16+x containing 20% by weight of Au, Ag, or Pt-group metals indicate that Au and the Ptgroup metals significantly suppress or eliminate the superconducting transition in BiSr•Ca•Cu•O.
Abstract: The Bi‐Sr‐Ca‐Cu‐O superconductors have been doped with various noble metals and their superconducting properties have been investigated. The resistivity and magnetic susceptibility measurements on sintered Bi4Sr3Ca2Cu4O16+x containing 20% by weight of Au, Ag, or Pt‐group metals indicate that Au and the Pt‐group metals significantly suppress or eliminate the superconducting transition in Bi‐Sr‐Ca‐Cu‐O. Only Ag is found to be benign, maintaining both the 115 and 85 K transitions in the compound. This nonpoisoning behavior of silver is of significant technical importance because of the need for a proper stabilizing normal metal for composite superconductor wire, nonreactive crucible materials for melt processing or crystal growth, and suitable nonpoisonous substrates or barriers for thin‐ or thick‐film superconducting devices.

222 citations


Network Information
Related Topics (5)
Oxide
213.4K papers, 3.6M citations
92% related
Nanoparticle
85.9K papers, 2.6M citations
92% related
Graphene
144.5K papers, 4.9M citations
91% related
Adsorption
226.4K papers, 5.9M citations
91% related
Carbon nanotube
109K papers, 3.6M citations
90% related
Performance
Metrics
No. of papers in the topic in previous years
YearPapers
2023485
2022986
2021622
2020724
2019896
2018767