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微孔/介孔复合分子筛的合成及其对CO2的吸附性能 总被引:1,自引:0,他引:1
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. 相似文献
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Adsorption of N2, CH4, C2H6, C3H8, and their mixture on zeolite NaX was studied by the volumetric method under static conditions at 278 K in the pressure range from 0.1 to 0.8 MPa. Compressibility factors were calculated in order to take into account the nonideal character of the gas phase. Adsorption isotherms of individual gases and partial isotherms were obtained. The adsorption properties of gases in the adsorption of a mixture and its components were compared. The selectivity coefficient of adsorption of propane in the N2-CH4-C2H6-C3H8-NaX system was calculated, and its dependence on the total pressure was determined.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 4, pp. 839–841, April, 1996. 相似文献
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The dependences of the differential molar isosteric heat of adsorption and entropy of adsorption of CO2 on zeolite NaX were determined in wide temperature (196–423 K) and pressure (0.1 Pa to 5.4 MPa) intervals. In the initial region of adsorption (a < 1 mmol g–1), the differential molar heat of adsorption increases from 40 to 43 kJ mol–1 and then decreases to 33 kJ mol–1. The heat of adsorption remains virtually unchanged at 3 mmol g–1< a < 6.5 mmol g–1 and decreases sharply at high fillings of zeolite micropores (a > 7 mmol g–1). The heat of adsorption was found to be temperature-dependent. The region with the constant heats shrinks with the temperature increase, and the heats begin to decrease at lower fillings of micro pores. The dependences of the change in the differential entropy of the adsorption system on the amount adsorbed were calculated at different temperatures. The specific features of the behavior of the thermodynamic functions of this adsorption system in the initial and medium region of fillings kre associated with interactions of adsorbate molecules with Na+ cations and walls of large cavities. For high fillings, an increase in repulsion forces between adsorbed molecules results in a sharp expansion of the adsorbent and a decrease in the heat of adsorption.Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 8, pp. 1570–1573, August, 2004. 相似文献
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The— function (energy level function) which represents surface heterogeneity was derived from theq— function (experimental heat function) in the case of reversible adsorption. The Langmuir equation was extended and applied to the procedure of calculations. An iterative calculation led to the most probable— function by setting theq— function and adsorption temperature. As an example for actual cases, the— function of Na-Y zeolite was calculated from theq— function obtained by the measurement of heats of adsorption of ammonia at 373 K. The— function thus derived seemed to be consistent with the positional distribution of sodium ions. 相似文献
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类水滑石Ti/Li/Al-LDHs的制备及其CO吸附性能 《燃料化学学报》2016,44(8):1017-1024
采用共沉淀法制备了一系列新型的类水滑石Ti/Li/Al-LDHs材料,通过原子吸收光谱(AAS)、X射线衍射(XRD)、扫描电镜(SEM)、热重分析(TG)和傅里叶变换红外光谱(FT-IR)等技术对其进行了表征,研究了不同金属元素比例和焙烧温度对该Ti/Li/Al-LDHs材料的结构、形貌及其CO_2吸附性能的影响。结果表明,当Ti/Li/Al比为1∶3∶4时,水滑石Ti/Li/AlLDHs的结晶度最好,形貌最规整,而Ti/Li/Al比为1∶3∶2、300℃下焙烧后得到的Ti_1Li_3Al_2-LDHs_(300)的CO_2吸附性能最好。Ti_1Li_3Al_2-LDHs_(300)上CO_2吸附量可达53.5 mg/g,10次循环吸附后,CO_2吸附量仅下降了2.4%。 相似文献