Irfan Muhammad Faisal, Goo Jeong Hoi, Kim Sang Done, Hong Sung Chang
Department of Chemical and Biomolecular Engineering, Energy and Environment Research Center, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 305-701, Republic of Korea.
Chemosphere. 2007 Jan;66(1):54-9. doi: 10.1016/j.chemosphere.2006.05.044. Epub 2006 Jul 7.
The oxidation characteristics of NO over Pt/TiO2 (anatase, rutile) catalysts have been determined in a fixed bed reactor as a function of O2, CO and SO2 concentrations in the presence of 8% water. The conversion of NO to NO2 increases with increasing O2 concentration up to 12% and it levels off. This saturation effect is more pronounced over rutile-Pt/TiO2 (r-Pt/TiO2) than that of anatase-Pt/TiO2 (a-Pt/TiO2). The presence of CO increases NO oxidation significantly and this enhanced effect is more pronounced on a-Pt/TiO2 than that on r-Pt/TiO2 with increasing CO concentration at lower temperatures. The same effect is also observed on the catalysts with different Pt and tungsten oxide (WO3) loadings. With increasing Pt and WO3 loadings on TiO2 support (Pt-WO3/TiO2), formation of NO2 is high even at lower temperatures. The presence of SO2 significantly suppresses the oxidation of NO over both r-Pt/TiO2 and a-Pt/TiO2 catalysts but it is less pronounced due to low stability of sulfate on a-Pt/TiO2.
在固定床反应器中，已测定了在8%水存在的情况下，NO在Pt/TiO₂（锐钛矿型、金红石型）催化剂上的氧化特性，该特性是O₂、CO和SO₂浓度的函数。NO向NO₂的转化率随O₂浓度增加至12%而升高，之后趋于平稳。这种饱和效应在金红石型Pt/TiO₂（r-Pt/TiO₂）上比在锐钛矿型Pt/TiO₂（a-Pt/TiO₂）上更明显。CO的存在显著提高了NO的氧化，在较低温度下，随着CO浓度增加，这种增强效应在a-Pt/TiO₂上比在r-Pt/TiO₂上更明显。在具有不同Pt和氧化钨（WO₃）负载量的催化剂上也观察到了相同的效果。随着TiO₂载体上Pt和WO₃负载量的增加（Pt-WO₃/TiO₂），即使在较低温度下NO₂的生成量也很高。SO₂的存在显著抑制了r-Pt/TiO₂和a-Pt/TiO₂催化剂上NO的氧化，但由于硫酸盐在a-Pt/TiO₂上的稳定性较低，这种抑制作用不太明显。
