title: Effects of surface features on sulfur dioxide adsorption on calcined NiAl hydrotalcite-like compounds.
abstract: 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-base 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-basic 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.
authors: Key Laboratory of Industrial Ecology and Environmental Engineering (MOE) and State Key Laboratory of Fine Chemical, School of Environmental Science and Technology, Dalian University of Technology, Dalian, 116024, China.
authors: Ling
authors: L
authors: Zhao
authors: Xinyong
authors: X
authors: Li
authors: Xie
authors: X
authors: Quan
authors: Guohua
authors: G
authors: Chen