Molybdenum metallic nanoparticle

Giovanni M, Pumera M (2011) Molybdenum metallic nanoparticle detection via differential pulse voltammetry. Electrochem Commun 13 203-204... 

The metal ion - metal nanocluster ensemble sites can contain either one or two metal components. In different forms of copper and gold catalysts, the metal can exist in both forms, i.e., as metal ion and the metal nanocluster. These systems will be considered as a mono-element metal ion - metal nanocluster ensemble sites. However, as it will be demonstrated later, systems containing two elements are more common. In most of these systems the metal ions are formed from elements of well known red-ox metals, such as tin, rhenium, iron, tungsten, molybdenum, etc. while the metal nanoparticles are noble metals, such as platinum, ruthenium, etc. 

One of the key discoveries during the first Raman experiments with cells that allowed control of the sample environment was a demonstration of the influence of moisture on the spectra of some catalysts. For example, supported metal oxide catalysts exhibit different Raman spectra depending on the loading of the metal oxide, such as molybdenum oxide. When the Raman spectra were recorded under ambient conditions, the spectra of the catalysts with low molybdenum loadings indicated the presence of monomolybdates, as characterized by the prominent band at about 900 cm-1. In contrast, polymolybdates, indicated by Raman bands between 930 and 960 cm-1, were detected at intermediate loadings, and crystalline M0O3 nanoparticles were found in materials with high... 

More publications were found related to carbides. First, Suslick s early report [64] that certain carbonyls sonicated in a decalin solvent under argon. For Fe and Co, nanostructured metals are formed for Mo and W, metal carbides (e.g., M02C) are produced. Molybdenum carbide was used later as a catalyst. The selectivity and catalytic activity of the Mo and W carbides was examined in the dehydrogenation of alkanes [140]. Another carbide that has already been mentioned is that of Pd [65], which was prepared by Maeda s group. Iron carbide was a byproduct that served as protective layer in Nikitenko s work on air-stable iron nanoparticles [70]. 

Epoxidation. New metal specimens for activating r-BuOOH to epoxidize alkenes include molybdenum oxide (with R3PO), and nanoparticles thereof. They have the advantage of being paramagnetic. 

Pdioo-xMox/C nanoparticle catalysts were synthesized by a simultaneous thermal decomposition with palladium acetyla-cetonate, platinum acetylacetonate, and molybdenum carbonyl in o-xylene in the presence of Vulcan XC-72R carbon. At first, the metal precursor and carbon support were mixed together and refluxed and Anally dried, followed by a heat treatment up to 900 °C in H2 atmosphere. ... 

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