Removal of NOx by photocatalytic processes

The photocatalytic methods for nitrogen oxides removal were recently very intense areas of scientific research. Photo-deNO(x) processes offer interesting ways for abatement of these harmful gases. This review describes several methods for removing NO by photocatalytic reactions. These methods can be classified into three major groups: photo selective catalytic reduction (photo-SCR), photo-oxidation and photodecomposition. The application of photocatalysts and photo-processes for NOx abatement in real-scale cases are presented. The fast-growing development of these methods is revealed by the large number of issued patents in photo-deNO(x) applications. The mechanism of NO creation and the traditional methods (Primary and secondary) of NOx removal are summarized and discussed. A cooperative system that combines the traditional (thermal) process and a photo-process is then proposed for improving NOx removal efficiency. (C) 2012 Elsevier B.V. All rights reserved.