Investigation of the Performance of V-W Based Catalysts at Low Temperature for NOx Reduction with NH₃

Abstract

The most potential method of selective catalytic reduction (SCR) to remove NOx from diesel engine emissions is very effective in NOx reduction with an efficiency up to 95%. However, the current SCRs have a limitation on operation temperature and a narrow operation temperature window. In this paper, the V-W based catalysts were used in the investigation to improve the low temperature performance of NOx conversion by doping Cu and Mn into V-W based catalyst. The temperature range studied was between 150 °C and 550 °C with an interval of 50 °C. The honeycomb catalysts were prepared by an impregnation method. The study also included characterization of catalysts by BET, XRD, TPD and XPS methods.It is found that NOx conversion performance of the V-W based catalyst increases with the increase of reaction temperature. After the metal Cu or Mn doped into the catalyst, it offers an improvement in the catalytic performance. Among all the catalysts studied, the mixed metal catalyst of Cu-Mn-V-W catalyst 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.