the silica supported platinum nanoparticles was synthesized by using the sol-gel method. the possibility of using diamminedinitro platinum (ii) as pt precursor and effect of metal precursor concentration on the final pt nanoparticle size was investigated. a stable silica sol was prepared via hydrolysis of tetraethyl orthosilicate (teos) as a metal alcoxide and condensation reaction. subsequentl...

The silica supported platinum nanoparticles was synthesized by using the sol-gel method. The possibility of using diamminedinitro platinum (II) as Pt precursor and effect of metal precursor concentration on the final Pt nanoparticle size was investigated. A stable silica sol was prepared via hydrolysis of tetraethyl orthosilicate (TEOS) as a metal alcoxide and condensation reaction. Subsequentl...

BACKGROUND South Africa is the largest producer of platinum group metals in the world. Platinum is found in the Bushveld Complex in the north-east of the country. This volcanic intrusion contains many other minerals, including crystalline silica. Little is known about the health risks in the platinum mining industry. AIMS To explore the potential for platinum mine workers to develop silicosis...

Square-planar polypyridine platinum(II) complexes have been introduced into a silica/polymer matrix by covalent ligand modification. The photophysical properties of the supported matrices are well retained as their model complexes, and the quantum yields for singlet oxygen ((1)O(2)) generation are comparable with that of TPP (tetraphenylporphyrin) under similar conditions. A preliminary applica...

A range of catalysts comprising of platinum supported on silica, prepared by an impregnation method, have been studied for the total oxidation of naphthalene, which is a representative Polycyclic Aromatic Hydrocarbon. The influence of platinum loading and calcination temperature on oxidation activity was evaluated. Increasing the platinum loading up to 2.5 wt.% increased the catalyst activity, ...

The CO preferential oxidation (PrOx) is one of the critical steps in hydrogen production and purification for Polymer Electrolyte Membrane Fuel Cell (PEMFC). This reaction was investigated in the presence of excess hydrogen over Cu/CeO2, Pt/CeO2 and Cu-Pt/CeO2 catalysts. The ceria supports was prepared via precipitation method and Cu-Pt/CeO2 catalyst was synthesized by sequential impregnation o...

Understanding the interactions between metal complexes and oxide surfaces is crucial to the synthesis of supported metal catalysts. Recently developed in situ techniques have made it possible to closely characterize the solid/liquid interface. For the first time, the adsorption of platinum complexes on alumina and silica has been probed using a quartz crystal microbalance; we were able to obser...

We developed a method for production of arrays of platinum nanocrystals of controlled size and shape using templates from ordered silica bead monolayers. Silica beads with nominal sizes of 150 and 450 nm were self-assembled into monolayers over strontium titanate single crystal substrates. The monolayers were used as shadow masks for platinum metal deposition on the substrate using the three-st...