摘要
In this study, titanium dioxide supported by multi-walled carbon nano tubes(MWCNTs/TiO_2) and Cr-doped TiO_2 supported by MWCNTs(MWNTs/Cr-TiO_2) were synthesized by the sol-gel method. The prepared samples were characterized by transmission electron microscopy, X-ray photoelectron spectroscopy, X-ray diffraction, the BrunauerEmmett-Teller analysis, and the Raman spectroscopy. The oxidation and efficiency for removal of SO_2 in a simulated flue gas were investigated experimentally in a fixed-bed reactor. The 15% MWCNTs/Cr-Ti02 sample displayed excellent adsorption properties, and a SO_2 removal rate equating to 30.415 1 mg/g from the simulated flue gas containing 2 300 μg/g of SO_2, 8% of 02, and 5% of H20 was achieved under optimal conditions covering a temperature of 333.15 K, and a space velocity of 1 275 h^(-1). The adsorption process was enhanced because Cr doping modified the pore structure and inhibited the grain growth of TiO_2. In addition, the Freundlich and Langmuir models revealed that SO_2 was mainly adsorbed through chemical adsorption on the sample surfaces, and the thermodynamic model analysis indicated that the adsorption was a spontaneous, exothermic, and entropy-reducing process. The adsorption kinetics of SO_2 can be described by the pseudosecond-order kinetic and the Bangham dynamics models. The possible reaction mechanism involved in desulfurization process was also proposed.
In this study, titanium dioxide supported by multi-walled carbon nano tubes(MWCNTs/TiO_2) and Cr-doped TiO_2 supported by MWCNTs(MWNTs/Cr-TiO_2) were synthesized by the sol-gel method. The prepared samples were characterized by transmission electron microscopy, X-ray photoelectron spectroscopy, X-ray diffraction, the BrunauerEmmett-Teller analysis, and the Raman spectroscopy. The oxidation and efficiency for removal of SO_2 in a simulated flue gas were investigated experimentally in a fixed-bed reactor. The 15% MWCNTs/Cr-Ti02 sample displayed excellent adsorption properties, and a SO_2 removal rate equating to 30.415 1 mg/g from the simulated flue gas containing 2 300 μg/g of SO_2, 8% of 02, and 5% of H20 was achieved under optimal conditions covering a temperature of 333.15 K, and a space velocity of 1 275 h^(-1). The adsorption process was enhanced because Cr doping modified the pore structure and inhibited the grain growth of TiO_2. In addition, the Freundlich and Langmuir models revealed that SO_2 was mainly adsorbed through chemical adsorption on the sample surfaces, and the thermodynamic model analysis indicated that the adsorption was a spontaneous, exothermic, and entropy-reducing process. The adsorption kinetics of SO_2 can be described by the pseudosecond-order kinetic and the Bangham dynamics models. The possible reaction mechanism involved in desulfurization process was also proposed.
基金
financially supported by the National Natural Science Foundation of China (No. 51706091)
the Open Foundation of Key Laboratory of Industrial Ecology and Environmental Engineering, MOE of China (No. KLIEEE-18-04)
the Talent Scientific Research Fund of LSHU(No. 2018XJJ-011)
the PhD Research Startup Foundation of Liaoning Shihua University (No. 2016XJJ-025)
