Qiuyu Feng

Low temperature catalytic oxidation of volatile organic compounds: a review

Volatile organic compounds (VOCs) are toxic and recognized as one of the major contributors to air pollution. The development of efficient processes to reduce their emissions is highly required. Complete catalytic oxidation is a promising way to convert VOCs, especially with low concentration, into harmless CO2 and water. This reaction is highly desirable to proceed at low temperature for the consideration of safety, energy savings, low cost and environmental friendliness. Great efforts have been devoted to develop efficient catalysts in order to reduce the temperature of catalytic oxidation of VOCs. The present review highlights recent important progress in the development of supported noble metal and metal oxide catalysts in this field. We examined several typical metals that are widely adopted as essential components for catalytic oxidation of VOCs and explored the effect of some important influencing factors such as the properties of metal and support, dispersion, particle size and morphology of metals. The specific mechanism that leads to superior catalytic activity towards low temperature VOC oxidation was discussed too.

Effect of redox state of Ag on indoor formaldehyde degradation over Ag/TiO2 catalyst at room temperature

Ag/TiO2 catalysts were prepared via in-situ synthesis and impregnation methods. The effect of redox state of Ag species on catalytic activity of Ag/TiO2 catalysts was studied. The Ag-i-300 catalyst with partially oxidized state of Ag species shows superior catalytic activity, keeping HCHO removal efficiency at an extraordinary level of 100% during the 200 mins reaction. The Ag/TiO2 catalysts were characterized by XPS, UV-Vis, BET, XRD, TEM, and in-situ DRIFTS technologies. XPS and TEM results exhibit that the partially oxidized state of Agδ+ (0 < δ < 1) and high dispersion of Ag species are beneficial for the oxidation of HCHO over Ag/TiO2 catalysts. According to the above results, a reaction pathway for HCHO oxidation over Ag-i-300 catalyst was also proposed.