State of the art in the development of catalytic processes for the selective catalytic reduction of NOx into N2

The selective reduction of NOx to nitrogen (DeNOx) is a known technology for eliminating this pollutant from both stationary and mobile sources, but it is still a relevant target in catalysis research and an open problem to meet the future exhaust emission regulations, in particular, for emissions from diesel engines. This chapter will introduce the topics, critically analyzing the state-of-the-art and the different strategies involved in reducing NOx, emissions. More specific discussions, particularly on the reaction mechanism and new technical developments, have been made in the following chapters. The effort is to identify the pros and cons in the research in the sector and to outline the areas where there is a need to intensify the research effort.