焙烧温度对负载型NiO/ZnO-TiO_(2)吸附剂结构及吸附脱硫性能的影响

Effect of calcination temperature on structure and adsorption desulfurization performance of supported NiO/ZnO-TiO_(2) adsorbent

采用等体积浸渍法制备NiO/ZnO-TiO_(2)汽油脱硫吸附剂,吸附剂前体通过不同温度焙烧得到成型吸附剂。考察焙烧温度对NiO/ZnO-TiO_(2)吸附剂脱硫活性的影响,并采用X射线衍射(XRD)、压汞、H_(2)程序升温还原(H_(2)-TPR)和H_(2)程序升温脱附(H_(2)-TPD)等手段对吸附剂进行表征。结果表明随焙烧温度升高,NiO与载体相互作用增强,活性组分NiO颗粒粒径增大,但TiO_(2)的存在一定程度上抑制了NiO迁移烧结;焙烧温度过高或过低都不利于吸附剂孔道形成,比表面积降低不利于脱硫过程;当焙烧温度为500℃时,吸附剂具有最大比表面积31.02 m^(2)/g,脱硫活性最佳,穿透时间和穿透硫容分别为152 h和11.21%。

An equal volume impregnation method was used to prepare NiO/ZnO-TiO_(2) gasoline desulfurization adsorbents,and the adsorbent precursors were calcined at different temperatures to obtain adsorbents.The effects of different calcination temperatures on the desulfurization activity of NiO/ZnO-TiO_(2) adsorbents were investigated.The adsorbents were characterized by X-ray diffraction(XRD),H_(2)-temperature-programmed desorption(H_(2)-TPD)and H_(2)-temperature-programmed reduction(H_(2)-TPR).The results show that the interaction between NiO and the support enhances with the increase of calcination temperature,and the size of active component NiO improves.However,the existence of TiO_(2) inhibits the migration and sintering of NiO to some extent.Too high or too low calcination temperature is not favorable for the formation of the adsorbent pores,which reduces the specific surface area and is not conducive to the desulfurization process.When the calcination temperature is 500℃,the adsorbent has a maximum specific surface area of 31.02 m^(2)·g^(-1),and the desulfurization activity is the best.The breakthrough time and the breakthrough sulfur capacity are 152 h and 11.21%,respectively.