摘要
CuSO4/TiO2 catalysts with high catalytic activity and excellent resistant to SO2 and H2 O,were thought to be promising catalysts used in Selective catalytic reduction of nitrogen oxides by NH3.The performance of catalysts is largely affected by calcination temperature.Here,effects of calcination temperature on physicochemical property and catalytic activity of CuSO4/TiO2 catalysts were investigated in depth.Catalyst samples calcined at different temperatures were prepared first and then physicochemical properties of the catalyst were characterized by N2 adsorption-desorption,X-ray diffraction,thermogravimetric analysis,Raman spectra,Fourier-transform infrared spectroscopy,X-ray photoelectron spectroscopy,temperature-pro grammed desorption of NH3,temperature-programmed reduction of H2 and in situ diffuse reflectance infrared Fourier transform spectroscopy.Results revealed that high calcination temperature had three main effects on the catalyst.First,sintering and anatase transform into rutile with increase of calcination temperature,causing a decrement of specific surface area.Second,decomposition of CuSO4 under higher calcination temperature,resulting in disappears of Br(?)nsted acid sites(S-OH),which had an adverse effect on surface acidity.Third,CuO from the decomposition of CuSO4 changed surface reducibility of the catalyst and favored the process of NH3 oxidation to nitrogen oxides(NOx).Thus,catalytic activity of the catalyst calcined under high temperatures(≥600℃)decreased largely.
基金
supported by the National Natural Science Foundation of China(Nos.21906127,21677114,21876139 and 21922606)
the Key R&D Program of Shaanxi Province(Nos.2019SF-244 and 2019ZDLSF05-05-02)
the China PostdoctoralScience Foundation(No.2016M602831)
Natural Science Foundation of Shaanxi Province,China(No.2019JQ-502)
the Fundamental Research Funds for the Central Universities(Nos.xjj2017113 and xjj2017170)
financial supports from the China Scholarship Council
the support of K.C.Wong Education Foundation