Abstract
A catalyst 0.1VP(0.2)O-Cr(0.01)-PEG(1×10-4)/Ti for low-temperature SCR de-NOx was developed and the effects of SO2 and water vapor on its catalytic activity were investigated. Cr doping increases the molar ratio of V5+ to V4+ on the VPO catalyst, which promote oxidation of NO to NO2 and catalytic activity of the VPO catalyst. An appropriate amount of redox-coupled V5+/V4+ also promotes catalytic activity of the VPO catalyst. The denitration efficiency over 0.1VP(0.2)O-Cr(0.01)-PEG(1×10-4)/Ti was above 98% at 150-350℃. Cr doping also promotes the generation of Lewis acid around V5+ center and BrOnsted acid (P-OH) on the VPO catalysts. The strong surface acidity of 0.1VP(0.2)O-Cr(0.01)-PEG(1×10-4)/Ti could restrain the adsorption of and oxidation of SO2. Characterization (FT-IR, TG) results indicate that nearly no sulfate was deposited on the surface of 0.1VP(0.2)O-Cr(0.01)-PEG(1×10-4)/Ti after activity test. The competitive adsorption of water molecules and nitric oxide on the catalyst surface decreases the catalytic activity of the VPO catalyst. The addition of Cr and PEG could increase the surface area and the exposure of active site of VPO catalyst, which also increase the unoccupied active sites of VPO catalysts in the presence of water vapor. The catalyst 0.1VP(0.2)O-Cr(0.01)-PEG(1×10-4)/Ti for low-temperature SCR de-NOx shows high catalytic activity and exhibits high resistance to SO2 and water vapor.
Highlights
In addition to coal-fired flue gas, industrial waste gases such as coke oven flue gas, sintering flue gas, and garbage incineration flue gas are other major sources of NOx (Chen et al, 2015; Gamrat et al, 2016; Li et al, 2018)
Busca et al investigated the oxidation of alkanes with Vanadium phosphorus oxides (VPO) and the results show that there are abundant Brønsted acid sites (V-OH, promote the formation of a Brønsted acid (P-OH)) on the surface of VPO catalyst (Busca et al, 1986; Bond, 1991; Feng et al, 2015)
The NH3-selective catalytic reduction (SCR) deNOx activity of the catalysts were tested at 500 ppm of NH3, 500 ppm of nitric oxide (NO), 6 vol.% of O2, and 15,000 h−1 GHSV
Summary
In addition to coal-fired flue gas, industrial waste gases such as coke oven flue gas, sintering flue gas, and garbage incineration flue gas are other major sources of NOx (Chen et al, 2015; Gamrat et al, 2016; Li et al, 2018). Optimizing the structure and specific surface area of the catalyst could increase its catalytic activity in the presence of water vapor.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
