Tungsten Doped Manganese Dioxide for Efficient Removal of Gaseous Formaldehyde at Ambient Temperatures
Summary:Fang Liu, Ranran Cao, Shaopeng Rong, Pengyi Zhang
Room-temperature active catalysts are very important to combat against ubiquitous indoor HCHO pollution. Here, tungsten doped MnO2 (W-MnO2) was first synthesized and investigated for HCHO decomposition at ambient temperature. With addition of WCl6 as precursor into the mixture of permanganate and manganese chloride, tungsten-doped δ-MnO2 with weak crystallinity and large specific surface area (>230 m2/g) was synthesized. Substitution of W6+ for Mn in MnO6 groups reduced the chemical valence of Mn and made adsorbed surface oxygen species more active. As a result, the W-MnO2 catalyst with the nominal W/Mn ratio achieved efficient and stable activity for real-level indoor HCHO (0.3 mg/m3) under the GHSV as high as 600 L/gcat·h, the removal efficiency reaching 90% at 30 °C and 60% at 5 °C, respectively.
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