微孔/介孔复合分子筛的合成及其对CO2的吸附性能

采用两步晶化法将合成的沸石前驱液(S)或沸石固体粉末(P)经不同浓度(c)的NaOH处理后, 分别以表面活性剂十六烷基三甲基溴化铵(CTAB)软模板或介孔炭(Meso-C)硬模板为导向剂, 自组装合成S-β-MCM41(c)、P-β-MCM41(c)、P-ZSM-MCM41(c)、P-ZSM-C系列微孔/介孔复合分子筛. 考察了沸石分子筛种类、碱处理液浓度以及介孔模板剂对合成复合分子筛结构与性能的影响. X射线衍射(XRD)、透射电子显微镜(TEM)和氮气吸附-脱附表征结果表明产物具有微孔/介孔多级孔结构. 该材料对CO₂的吸附能力比纯微孔或介孔材料均有明显提高, 其中P-ZSM-MCM41(2)的CO₂吸附容量最大可达1.51 mmol·g^-1, 为ZSM-5沸石吸附量的两倍多.

Synthesis of Micro/Mesoporous Composites and Their Application as CO2 Adsorbents

We synthesized a series of micro/mesoporous composites of S-β-MCM41(c),P-β-MCM41(c),P-ZSM-MCM41(c),P-ZSM-C through a two-step crystallization process.During this process,the microporous zeolite precursor solution (S) or the zeolite powder (P) was first synthesized and treated with NaOH solution with different concentration (c),and then the mesopores were induced by hexadecyltrimethylammoniumbromide (CTAB) as a soft template or mesoporous carbon as a hard template.The effects of the type of inorganic precursor,the base concentration,and the type of mesoporous template on the structure and property of the micro/mesoporous composites were investigated.The results of X-ray diffraction (XRD),transmission electron microscopy (TEM),and nitrogen adsorption-desorption isotherms showed that the products contained micropores and mesopores,simultaneously.The CO2 adsorption capacities of these micro/mesoporous composites were obviously improved compared to the pure microporous or mesoporous materials.Among them,P-ZSM-MCM41(2) had the highest CO2 adsorption capacity of 1.51 mmol · g-1,which was almost twice that of the original ZSM-5.