Vanadium oxide nanotubes for selective catalytic reduction of NOx with NH3

Abstract

Vanadium oxide (VOx) nanostructures, synthesized by hydrothermal treatment using dodecylamine as template, were evaluated for the selective catalytic reduction of NOx with ammonia (NH3-SCR). The effect of solvent type in the reaction mixture (EtOH/(EtOH+H2O)) and time of hydrolysis was studied. The obtained materials were characterized by XRD, SEM, TEM and BET. The VOx nanorods (80–120nm diameter and 1–4μm length) were synthesized in 25vol% EtOH/(EtOH+H2O) and the open-ended multiwalled VOx nanotube (50–100nm inner diameter, 110–180nm outer diameter and 0.5–2μm length) synthesized in 50vol% EtOH/(EtOH+H2O). VOx nanotubes performed the superior NH3-SCR activity under a gas hourly space velocity of 12,000h−1 at low temperature of 250°C (NOx conversion of 89% & N2 selectivity of 100%), while most of the developed Vanadia base catalysts are active at high temperature (>350°C). The superior NH3-SCR activity of VOx nanotubes at low temperature is related to nanocrystalline structure, special nanotube morphology as well as high specific surface area.