MOFs负载ACF吸附剂的制备及H_(2)S脱除特性

Preparation and H_(2)S removal properties of ACF adsorbent supported by MOFs

将活性炭纤维(ACF)负载到金属有机框架材料MOF-199上,在水热条件下制备了MOF-199@ACF吸附剂,利用固定床反应装置评价其脱H_(2)S性能;采用氮气吸/脱附、XRD、EDS、SEM、XPS表征和分析了MOF-199@ACF的物相组成;考察了ACF负载量、吸附温度、相对湿度对MOF-199@ACF脱除H_(2)S性能的影响,探究了MOF-199@ACF在H_(2)S脱除中可能的反应机理。结果表明,与MOF-199相比,ACF负载量(质量分数)为1%的吸附剂MOF-199@1%ACF的H_(2)S出现时间从180 min延后至405 min,穿透硫容从7.2 mg/g提升至14.5 mg/g;ACF负载量为1%不会干扰MOF-199结晶形成的稳定结构,ACF参与配位使MOF-199@1%ACF表面粗糙化,导致更多的吸附位点暴露,增加了比表面积(从MOF-199的1108.6 m^(2)/g增至1978.3 m^(2)/g);MOF-199@1%ACF是以化学吸附的活化吸附为主,升高温度(30~70℃)有利于加快吸附速率;适量水气(相对湿度10%)有助于性能提升(穿透硫容14.8 mg/g)。

MOF-199@ACF adsorbent was prepared by loading activated carbon fiber(ACF)onto MOF-199 metal-organic frame material under hydrothermal conditions,characterized by nitrogen adsorption/desorption,XRD,EDS,SEM and XPS,and evaluated for its H_(2)S removal performance by a fixed bed reaction device.The effects of ACF loading capacity,adsorption temperature and relative humidity on the H_(2)S removal performance of MOF-199@ACF were investigated,the possible reaction mechanism was also explored.The results showed that compared with those of MOF-199,the H_(2)S emergence time of MOF-199@1%ACF was delayed to 405 min from 180 min,and the sulfur penetration capacity was increased from 7.2 mg/g to 14.5 mg/g.ACF with loading of 1%did not interfere with the stable crystallization structure of MOF-199,but roughened the MOF-199@1%ACF surface inducing more adsorption sites exposed and increasing the specific surface area(from 1108.6 m^(2)/g of MOF-199 to 1978.3 m^(2)/g).Adsorption by MOF-199@1%ACF was dominated by chemically activated adsorption,with adsorption rate increasing with temperature rise(30~70℃).Meanwhile,a moderate amount of water vapor(relative humidity 10%)could help to improve performance(penetration sulfur capacity 14.8 mg/g).