|Parto Farazan Avije Kimiya|
Automotive Auto PartsAutomotive Catalyst
PalladiumPd Nanoparticle /Nanopowder CAS Number : 7440-05-3
RhodiumRh Nanoparticle /Nanopowder CAS Number : 7440-16-6
The world-wide increase in automobile usage is directly correlated with the population increase and thus more vehicular activity is present in densely populated areas. This has been shown to have implications on the health of individuals residing or working in polluted areas as it is well known that inhalation of polluted air, more specifically the Particulate Matter (PM) suspended in air, can cause detrimental health effects including cardiovascular and respiratory disease. A catalytic converter is an emissions control device that converts toxic gases and pollutants in exhaust gas to less toxic pollutants by catalyzing a redox reaction (an oxidation and a reduction reaction). The Platinum Group Metals (PGMs) (Ru, Os, Rh, Ir, Pd and Pt) are all present in very low concentrations in the earth’s upper crust. The main use of these metals is in automobile catalytic converters. Catalytic converters are constructed by depositing approximately 0.2wt% of PGMs on a honeycomb-cordierite substrate (MgO.Al2O3.2.5SiO2) covered by a washcoat of cordierite and γ-Al2O3. The high surface area of the honeycomb structure and that of the porous cordierite enables the exhaust gas to react with the PGM dispersed in the substrate material. Pt and Rh are used for reduction reactions while Pd and Pt are used for oxidation reactions and as their size fall into nano-scale, the catalytic activity increases considerably.