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BS III norms (BS IV in 13+26 cities) have been implemented in India for a long time. There have been discussions over further country wide implementation of BS IV norms. All the engine categories (on-road & off-road) will be required to comply with stringent norms in future sooner or later. The Original Equipment Manufacturers (OEMs) have been working to comply with the norms. There has been a lot of work in the field of power train, transmission, aerodynamics etc. in order to make application better in all possible ways. However it has been largely focused on engine optimization and vehicle improvisation. The time has come when industry is staring on implementation of stringent emission norms and it will be vital to look at it in a whole perspective. It would not be incorrect to say there have been little work been done specifically on after-treatment systems which has been built for Indian market and driving conditions.

From the recent past, automotive exhaust emission management strategies has been progressing towards an alternative for vanadia based selective catalytic reduction (V-SCR) of NOx in diesel powered vehicles. Some of the major inadequacies of existing V-SCR technology were as follows: poor thermal endurance (deteriorates at 550°-600°C), volatilization of harmful vanadium into environment and inadequate NO2 conversion. Metal incorporated zeolite systems, (the metals being preferably selected from transition metal elements), has gained momentum for commercial DeNOx applications. However, the major challenge with this zeolite SCR (Z-SCR) was its low thermal/hydrothermal stability. In the current study, it has been attempted to overcome this by various zeolites and metals combinations. Various combinations of metallic Z-SCR were extensively studied for their low and high temperature activities.

Current restrictions on environmental pollution worldwide has created the need for new methodologies and technology development which should not only ensure ultra-low emission level from different categories of engine but should also use less fuel resulting in lower carbon dioxide (CO2) emissions. The state-of-art technology to achieve ultra-low emissions placed after engine in exhaust line is a ‘catalytic converter’. Catalytic converter is an after treatment device which typically oxidizes or reduces the toxic pollutants emitted by any engine to carbon dioxide (CO2), nitrogen (N2) and water (H2O). Catalytic converters used in Gasoline / CNG operated vehicles contains oxygen storage component as a key component for supplying oxygen in rich mode of operation and the oxygen concentration release rate is function of gas concentration and air to fuel ratio (A/F) or lambda (λ).