V2O5-WO3 catalysts treated with titanium isopropoxide using a one-step co-precipitation method for selective catalytic reduction with NH3

Abstract

Selective Catalytic Reduction (SCR) of nitrogen oxides (NOx) is the most effective way to reduce NOx emissions. However, the most used catalysts for this purpose, V2O5-WO3/TiO2 (VWTi) hybrid system, have limited applicability owing to its narrow operating temperature range (300–400 °C). Therefore, catalysts with abundant active sites are needed to extend the temperature range to more acceptable values (200–400 °C). The number of active sites depends on the catalyst synthesis method. The aim of this study is to increase the dispersion of V-OH and W-OH through a one-step process, this is achieved by treating the TiO2 support with titanium isopropoxide (TTIP) and simultaneously incorporating the V-OH and W-OH. This synthesis method used here is expected to enhance the interaction between the support and V-OH and W-OH by increasing the number of catalytically active sites. This process is simple and could be applied for the catalyst manufacturing process in the industrial scale. The optimal performance observed for the catalysts prepared at a TTIP loading of 5 wt% using a one-step method is due to its higher catalytic activity at lower temperatures, the observed results could be explained based on the formation of abundant V-OH and W-OH functional groups and the V4+/V5+ ratio (≈1). The scope of this study is to develop a new catalyst for selective catalytic reduction of nitrogen oxides.