金属氧化物对SO2在活性炭表面吸附影响的实验研究

摘要

Effect of metallic oxides on adsorption of SO2 on activated carbon was studied at 150 ℃ using thermogravimetric method.Physical-chemical structure changes of metallic oxide-loaded coconut shell-based activated carbon were characterized by N2 adsorption and X-ray photoelectron spectroscopy (XPS).Results show that there is delay of SO2 adsorption due to the diffusion of SO2 from gas phase into pores.Both the distribution of active sites for SO2 adsorption and the equilibrium absorption capacity change significantly after the activated carbon being loaded with metallic oxides.The distribution of active sites in Ce-and Zr-loaded active carbon is relatively uniform,which is helpful to the enhancement of SO2 adsorption; while most active sites in Fe-,Co and Ni-loaded active carbon are located on the outside surface,resulting in a low utilization rate of internal pores and therefore a reduced capability in SO2 adsorption.%采用热重方法研究了150℃下金属氧化物对SO2在活性炭表面吸附的影响；对以椰壳为原料的活性炭进行了金属氧化物负载,并采用氮吸附与X射线光电子能谱(XPS)方法对负载后活性炭物理化学结构的变化进行了表征.结果表明:吸附过程存在一定的迟滞,这是由SO2从气相向孔隙扩散引起的；活性炭负载金属氧化物后,用于SO2吸附的活性位分布与平衡吸附量均发生了显著变化；负载Ce和Zr的活性炭活性位分布较均匀,有助于SO2吸附量的增加；而负载Fe、Co和Ni的活性炭活性位大部分位于外表面,导致内部孔隙利用率较低,因而抑制了SO2的吸附.