Effects of Surface Features on Sulfur Dioxide Adsorption on Calcined NiAl Hydrotalcite-like Compounds
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- 作者：Ling Zhao ; Xinyong Li ; Xie Quan ; Guohua Chen
- 刊名：Environmental Science & Technology
- 出版年：2011
- 出版时间：June 15, 2011
- 年：2011
- 卷：45
- 期：12
- 页码：5373-5379
- 全文大小：897K
- 年卷期：v.45,no.12(June 15, 2011)
- ISSN：1520-5851
文摘
The hydrotalcite-based NiAl mixed oxides were synthesized by coprecipitation and urea hydrolysis approaches and employed for SO2 removal. The samples were well characterized by inductively coupled plasma (ICP) elemental analysis, X-ray diffraction (XRD), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), and N2 adsorption/desorption isotherm analyses. The acid鈥揵ase properties were characterized by pyridine chemisorption and CO2 temperature-programmed desorption (TPD). The calcined NiAlO from the urea method showed excellent SO2 adsorption and its adsorption equilibrium showed a type I isotherm, which significantly improved the adsorption performance for low-concentration SO2. Both the physical structure and the acidic鈥揵asic sites were found to play important roles in the SO2 adsorption process. In situ Fourier transform infrared spectroscopy (FTIR) investigation revealed that adsorbed SO2 molecules formed surface bisulfite, sulfite, and bidentate binuclear sulfate. The mechanisms for SO2 adsorption and transformation are discussed in detail.