Cu-Al OXIDE NANOCOMPOSITE-BASED EXTERNAL FILTERS FOR GAS PURIFICATION FROM PETROL AUTOMOBILE EXHAUST

Currently existing exhaust gas catalytic converters in automobiles are expensive because they use precious metals, such as Pt, Pd, and Rh, as active components in conversion catalysts. However, they are unable to convert all toxic gases (e.g., CO, NOx, and hydrocarbons) into less harm -ful pollutants before emission to the atmosphere. This is more so in case of automobiles with old petrol engines and fuel types (standard unleaded petrol) causing air pollution. In this work, equimolar copper-aluminium oxide-based nanocomposites devoid of precious metals were pre-pared using cost-effective wet chemical methods rendering a nano crystalline-amorphous catalyst matrix and tested for NOx reduction. An external filter with the proposed catalyst was developed and used at the tailpipe of a 350 cc petrol engine to assess the impact on exhaust gas emissions. We also studied the growth and composition of chemically stable composite and analyzed their functional properties using X-ray diffraction, adsorption, and gas chromatography. Nanocom-posite was dip coated on ceramic honeycomb substrates and mounted inside welded casings to fabricate an external filter. Emission tests were carried out with and without the exhaust filter. A reduction in NOx along with that of CO and hydrocarbons from the flue gas by about 45, 12, and 32%, respectively, was obtained when the tailpipe emissions were treated at ambient conditions. To the best of our knowledge, this is one of the primary studies on a simple and well-designed Cu-Al oxide nanocomposite matrix for three-way catalysis during exhaust flue gas treatment.