Synthesis of CNTs based multi metal oxide catalyst for low temperature selective catalytic reduction of NOx with ammonia

Abstract

The continuous rise in the price of crude oil and the increased attention on fuel economy has urged vehicle manufacturers to concentrate on various lean burn and diesel engines. The tremendous growth of diesel engines in the automobile sector sequentially increases the global NOx emissions, one of the major environmental pollutants. It is also considered as one of the secondary greenhouse gases, reacting with the other atmospheric gases to produce ground-level ozone and photochemical smog. Moreover, NOx emissions lead to the formation of acid rain by reacting with water and atmospheric oxygen. As per the latest European and American emission standards, NOx emissions from both on and off-road vehicles are becoming increasingly stricter and thus need to be urgently addressed. For the past 3 decades, selective catalytic reduction has been the most widely used exhaust gas after-treatment technique to reduce NOx emissions from diesel exhaust. The basic principle behind this technique involves the reduction of harmful NOx emissions into N2 and H2O by using ammonia or urea as a reductant. To date, WO3 or MoO3 promoted, TiO2 supported, Vanadium based composite (V2O5-WO3(MoO3)/TiO2) is the most widely used SCR catalyst because of its excellent SCR activity at higher temperatures, wide operating temperature window, high sulfur tolerance and reasonable production cost. newline