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

Abstract

Current exhaust gas catalytic converters are expensive as it makes use of precious metals such as Platinum (Pt), Palladium (Pd) and Rhodium (Rh) as active components in conversion catalysts. However, these converters do not convert all toxic gases (e.g.: CO, NOX, HC) into less harmful pollutants, before emitting them to atmosphere, particularly for automobiles with old petrol engines and fuel types (standard unleaded petrol) causing more air pollution. In this work, equimolar Copper – Aluminium oxide-based nanocomposites were synthesised using wet chemical synthesis method and its effectiveness as a catalyst for removal of NOx gas was explored. An external filter with the proposed catalyst was fitted to the tailpipe of a 350-cc petrol engine and the impact on exhaust gas emissions was assessed. Chemical growth, composition of the nanocomposites prepared and the relevant functional properties were characterized using X-Ray Diffraction, Adsorption studies and Gas Chromatography. Nanocomposite was deposited on ceramic substrate, which was then mounted inside housing and connected to the tailpipe for testing. Emission tests were carried out with and without the exhaust filter. A reduction in NOx along with CO and HC components of the exhaust gas by about 45, 33 and 12% respectively was obtained when the proposed nanocomposite was used to treat the tailpipe emissions.