Pollution by nitrogen oxides: an approach to NOx abatement by using sorbing catalytic materials

This article summarises the abatement of NOx pollution by using sorbing catalytic materials with especial relevance to the challenge presented in fixed installations sources. A general vision of the origins of the different pollutants, with emphasis on nitrogen oxides formation, is presented as introduction. The impact of NOx pollution comprises additionally a quick view of its toxicity and environmental effects. Actual solutions are presented especially the case of the selective catalytic reduction (SCR) process with its advantages and difficulties. The new concepts for NOx abatement are also analysed. In such a way, updated information on solid sorbents for NOx removal is provided by including metal oxides, spinelles, perovskites, double-layered cuprates, zeolites, carbonaceous materials, heteropolyacids (HPAs), and supported heteropolyacids. The possibility of reducing those sorbed NOx is also underlined. Sorption mechanisms are analysed and clarified by emphasising convergence and disagreement points.