Evaluation of carbon nanotubes produced from toluene steam reforming as catalyst support for selective catalytic reduction of NOx

There is current interest in developing low cost, effective catalysts for the low temperature selective catalytic reduction (SCR) of nitrogen oxides (NOx). In this work, we have applied carbon nanotubes (CNTs), produced as a by-product of hydrogen production from the steam reforming of toluene (as a representative hydrocarbon), as a catalyst support for a V2O5–WO3 catalyst for SCR of NOx. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) analysis showed well dispersed metals on the surface of the CNTs. The V2O5–WO3/CNT catalyst has exhibited NOx reduction efficiency higher than 95% at reaction temperatures between 340 and 400 °C. However, there was a low NOx reduction at SCR reaction temperature of less than 200 °C which is suggested to be due to the lack of Lewis acid sites, as determined from NH3-TPD (temperature program desorption) analysis. Future work to lower the SCR reaction temperature with high NOx efficiency is suggested.