Investigation of the Performance of Fe-Based Catalysts for NOx Reduction with NH3

Abstract

Selective catalytic reduction (SCR) with ammonia is a well-proven technique for NOx removal in power stations. It is very effective in NOx reduction with an efficient up to 98%. However, the current SCRs have a limitation on operation temperature and a narrow operation temperature window.Metal Fe based catalysts were used in the investigation to improve the low temperature performance of NOx conversion. The temperature range studied was between 150 °C and 350 °C with an interval of 50 °C. The honeycomb catalysts were prepared by an impregnation method. The study also included characterization of catalysts by XRD, H 2 -TPR and SEM methods.It is found an increase in metal Fe content from 2 to 6 % wt. offers an improvement in the catalytic performance. However, a further increment in Fe content will result in a decrease in its performance. More than 90 % NOx conversion rate could be achieved over the Fe-based honeycomb catalyst at a low temperature by doping the catalysts with Ni and Zr at different weights. Among all the catalysts studied, the mixed metal catalyst of Fe-Ni-Zr is found the most potential one, not only because of its higher NOx conversion rate at a low temperature, but also because of its wider operation temperature window.