高稳定性介孔MgO-ZrO2纳米复合物对CO2吸附性能研究

CO_2 Adsorption over Mesoporous MgO-ZrO_2 Nanocomposites with High Stability

用溶胶-凝胶法制备了介孔MgO-ZrO2纳米复合物,并通过XRD、氮吸附和CO2-TPD等手段表征了材料的结构特征和表面性质。XRD、氮吸附结果表明此纳米复合物具有典型的介孔结构,比表面积达183-212 m^2/g,并且有较好的热稳定性,在700℃以下介孔孔道不会坍塌。另一方面,这种纳米复合物表面具有适中的碱性,其碱性位与基体结合牢固,稳定性好。由于其具有发达的孔隙和适中的碱性,二氧化碳在其表面的吸附量达1.6 mmol/g,且经数次循环后材料的吸附性能无明显下降。

A novel CO2 absorbent MgO-ZrO2 nanocomposites were synthesized via appropriate sol-gel process. The structure and surface properties of the as-prepared materials were characterized by XRD, N2 adsorption-desorption and CO2-TPD techniques. XRD and N2 adsorption-desorption results showed that the nanoeomposites possessed mesoporous framework and a surface area of 183 - 212 m^2/g, and their mesoporous framework was well preserved even after calcinations at 700 ℃. In addition, the nanocomposites exhibited appropriate basic strength and the basic sites were tightly anchored to the substrate, greatly improving the stability of the surface basicity. Owing to the advantages of the mesoporous structure and the surface basicity, the amount of CO2 adsorption over MgO-ZrO2 nanocomposites was up to 1.6 mmol/g and this material after multicycle runs of CO2 adsorption/ desorption kept almost the performance of the fresh samples.