Influence of Fe loadings on desulfurization performance of activated carbon treated by nitric acid

摘要

A series of Fe supported on activated carbon treated by nitric acid are prepared by incipient wetness impregnation with ultrasonic assistance and characterized by N-2 adsorption-desorption, X-ray diffraction, Fourier transform infrared spectrum and X-ray photoelectron spectroscopy. It has shown that Fe loadings significantly influence the desulfurization activity. Fe/NAC5 exhibits an excellent removal ability of SO2, corresponding to breakthrough sulfur capacity of 323mg/g. With the increasing Fe loadings, the generated Fe3O4 and Fe2SiO4 increase, but Fe-2(SO4)(3) is observed after desulfurization. Fe/NAC1 has a Brunauer-Emmett-Teller (BET) surface area of 925m(2)/g with micropore surface area of 843m(2)/g and total pore volume of 0.562cm(3)/g including a micropore volume of 0.300cm(3)/g. With the increasing Fe loadings, BET surface area and micropore volume decrease, and those of Fe/NAC10 decrease to 706m(2)/g and 0.249cm(3)/g. The Fe loadings influence the pore-size distribution, and SO2 adsorption mainly reacts in micropores at about 0.70nm. C=O and C-O are observed for all samples before SO2 removal. After desulfurization, the C-O stretching is still detected, but the C=O stretching vibration of carbonyl groups disappears. The stretching of S-O or S=O in sulfate is observed at 592cm(-1) for the used sample, proving that the existence of SO42-.