AUTHOR=Jia Yong , Yang Jianhua , Jiang Jin , Gu Mingyan , Zhi Yingying , Guo Lina , Chen Yihua TITLE=Investigation of the Effect of SO2 and H2O on VPO-Cr-PEG/TiO2 for the Low-Temperature SCR de-NOx JOURNAL=Frontiers in Materials VOLUME=6 YEAR=2019 URL=https://www.frontiersin.org/journals/materials/articles/10.3389/fmats.2019.00320 DOI=10.3389/fmats.2019.00320 ISSN=2296-8016 ABSTRACT=

A catalyst 0.1VP(0.2)O-Cr(0.01)-PEG(1 × 10⁻⁴)/Ti for low-temperature SCR de-NO_x 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°C. Cr doping also promotes the generation of Lewis acid around V⁵⁺ center and Brønsted 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-NO_x shows high catalytic activity and exhibits high resistance to SO₂ and water vapor.