Synergistic Elimination of NO x and Chloroaromatics on a Commercial V 2 O 5 –WO 3 /TiO 2 Catalyst: Byproduct Analyses and the SO 2 Effect

作者：Weiyu Jiang, Yulei Yu, Feng Bi, Pengfei Sun, Xiaole Weng, Zhongbiao Wu · 发表于：Environmental Science & Technology · 年份：2019 · DOI：10.1021/acs.est.9b04155 · 被引用次数：173 · 研究领域：Catalytic Processes in Materials Science、Catalysis and Oxidation Reactions、Catalysis and Hydrodesulfurization Studies

The synergistic control of multipollutants is the frontier of environmental catalysis. This research is in the infancy stage, and many uncertainties still remain. Herein, we investigated the reaction characteristics of synergistic elimination of NO x and chloroaromatics on a commercial V 2 O 5 –WO 3 /TiO 2 catalyst. The reaction byproducts were qualitatively and quantitatively analyzed, and their origins were clarified. In particular, the origins of polychlorinated dibenzo- p -dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) from the synergistic reaction with or without SO 2 were first explored; this is crucial for assessing the environmental risk by applying such a synergistic system. Experimental results indicate that during the synergistic reaction, the V 2 O 5 –WO 3 /TiO 2 catalyst was deactivated at 200 and 250 °C, whereas the 300 °C was sufficient to durably convert the NO and chlorobenzene at the turnover frequency (TOF) of 7.23 × 10 –4 and 1.32 × 10 –4 s –1, respectively. A range of aromatics, alkenes, and alkanes, particularly their chlorinated congeners, were observed in the off-gases and on the catalyst surface, where those of 3-chlorobenzonitrile, 4-chloro-2-nitrophenol, and inorganic CS 2 were first discovered. In the time-on-stream test at 250 °C, the PCDD/Fs collected from the off-gases was measured at 0.0514 ng I-TEQ Nm –3, but the most toxic dioxins congener, 2,3,7,8-TCDD, was not observed. The alkalinity of selective catalytic reduction reaction lik...