Development of Nanomaterial for Environmental Application

Abstract

Noble metal supported catalysts are work horses in the petroleum, petrochemical and environmental pollution abatement catalysts. Generally conventional methods are used for the preparation of such materials. To increase the efficacy of the above catalysts we have made an attempt to adopt preparation methods known in the nano science. Particularly, use of capping agents like PVP and also polyol methods in the preparation of Pt, Pt-Pd supported nano catalysts. A great interest at this time in the field of nanoscience is the dependence of the different properties of nanoparticles on their shape, size and also distribution. The morphology and particle size distribution of nanoparticles was found to play a crucial role in determining their catalytic properties. Platinum in nano forms play important role in many applications because of its extraordinary physico- chemical properties. For instance, it serves as a major catalyst in the industrial processes like reforming, oxidation, reduction and also selective oxidation. A major application, where mixer of noble metals used in the reduction of pollutant gases emitted from automobiles. All theses applications require the use of Pt in the finely divided state. For this reason, various chemical protocols have been developed for preparing nanoparticles. Variations used in our preparations are: 1) Methods of preparation ( PVP as capping agent, Polyol method) 2) Noble metal carriers (Alumina , Silica and β-Zeolite) 3) Preparation parameters studied are reflux duration, temperature and pH) 4) Noble metals (Pt, Pt-Pd bimetallics), Concentration of active metals Materials prepared are tested with ICP for bulk analysis, UV for noble metal oxidation state, TGA for possible compounds/ complexes and TEM for nano particle size and shape characterization. To know the catalytic properties of the materials prepared, we have chosen a model reaction of complete oxidation of propane under fixed HC/O2 ratio. Light of curve have been built based on experimental data. To make useful correlations, we have bench marked our samples with proven commercial catalyst, which is being used for the nitrogen purification by completely oxidizing the HC. Pt loading from 0.02 to 0.3% was investigated; out of these samples polyol 0.08 Pt-Alumina(E) was found to be most active iv catalyst. It is concluding that polyol 0.08 Pt- Alumina (E) gives light off temperature T97 at 2050 C and commercial catalyst at 4000C for combustion of propane under optimized conditions. Based on the above studies, we have zeroed on the above samples and proposed to test for commercial utilization.