多酸基UiO-66的合成及其对硫化氢的脱除性能

Heteropoly-Acid-Based Modified UiO-66:Its Synthesis

硫化氢具有较强的毒性和腐蚀性,高效脱除硫化氢对于工业生产、环境治理等过程意义重大。该文基于钼基杂多酸(HPAs),以UiO-66为载体,一步水热合成HPAs@UiO-66,构建不同活性中心多酸基固相脱硫体系,考察杂多酸结构(Keggin、Dawson)、中心原子(P、Si)、取代原子(V、W)对脱硫的影响,并通过BET、FT-IR、XRD、SEM、TEM进行理化性质分析。结果表明,PMo_(12)@UiO-66脱硫活性最高,且其脱硫能力在100℃时最佳,吸附量可达到17.18 mg/g,同时发现水分对其脱硫具有促进作用。与PMo_(12)和UiO-66相比,PMo_(12)@UiO-66表现出明显脱硫优势,其吸附量分别为PMo_(12)和UiO-66的7.5和14.2倍,证明了PMo_(12)与UiO-66具有协同脱硫作用。XPS结果表明,PMo_(12)与H_(2)S之间发生了氧化还原反应,H_(2)S在PMo_(12)氧化作用下被转化成单质硫。研究表明PMo_(12)的引入对UiO-66脱硫性能的强化作用最为显著,可为开发新型多酸基固相脱硫剂提供参考。

Hydrogen sulfide is characterized with strong toxicity and corrosivity,so it is important to efficiently minimize its pollution.In this laboratory experiment a series of HPAs@UiO-66 were prepared by one-step hydrothermal method with molybdenum-based heteropoly acid(HPAs)as active centers and UiO-66 as a carrier,and a multi-acid-based solid phase desulfurization system with various active centers was set up.The effects of Keggin and Dawson structures,the central atoms(P and Si),and the substitutional atoms(V and W)of HPAs on desulfurization performance were studied,and their physicochemical properties were analyzed by BET,FT-IR,XRD,SEM,and TEM.As a result,it was showed that PMo_(12)@UiO-66 had excellent desulfurization activity,its H_(2)S removal ability was maximized at 100℃with a absorbing capacity being able to reach 17.18 mg/g,and it was found the presence of water in the mixed gas can promote PMo_(12)@UiO-66 to remove H_(2)S.In comparison with PMo_(12)and UiO-66,PMo_(12)@UiO-66 was far better in desulfurization,its H_(2)S absorbing capacity was 7.5 and 14.2 times PMo_(12)and UiO-66,respectively,demonstrating the synergistic desulfurization effect of PMo_(12)and UiO-66.Analysis by use of XPS(X-ray photo-electron spectroscopy)showed that the redox reaction took place between PMo_(12)and H_(2)S,during which H_(2)S was converted into elemental sulfur due to the oxidizing action of PMo_(12).In conclusion,this study proved that the introduction of PMo_(12)had exhibited the most remarkable effect on enforcing the desulfurization performance of UiO-66,which could provide a reference for exploiting more novel HPA-based solid phase desulfurization agents.