Phosphotungstic Acid as a Dechlorination Agent Collaborates with CeO 2 for Synergistic Catalytic Elimination of NO x and Chlorobenzene.

The development of efficient technologies for the synergistic catalytic elimination of NO x and chlorinated volatile organic compounds (CVOCs) remains challenging. Chlorine species from CVOCs are prone to catalyst poisoning, which increases the degradation temperature of CVOCs and fails to balance the selective catalytic reduction of NO x with the NH 3 (NH 3 -SCR) performance. Herein, synergistic catalytic elimination of NO x and chlorobenzene has been originally demonstrated by using phosphotungstic acid (HPW) as a dechlorination agent to collaborate with CeO 2 . The conversion of chlorobenzene was over 80% at 270 °C, and the NO x conversion and N 2 selectivity reached over 95% at 270-420 °C. HPW not only allowed chlorine species to leave as inorganic chlorine but also enhanced the Bro̷nsted acidity of CeO 2 . The NH 4 + produced in the NH 3 -SCR process can effectively promote the dechlorination of chlorobenzene at low temperatures. HPW remained structurally stable in the synergistic reaction, resulting in good water resistance and long-term stability. This work provides a cheaper and more environmentally friendly strategy to address chlorine poisoning in the synergistic reaction and offers new guidance for multipollutant control.