Adsorption of carbon dioxide and nitrogen on zeolite rho prepared by hydrothermal synthesis using 18-crown-6 ether.
Adsorption of carbon dioxide and nitrogen on zeolite rho prepared by hydrothermal synthesis using 18-crown-6 ether.
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DOI：
10.1016/j.jcis.2012.06.061
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发表时间：
2012-12
影响因子：
9.9
通讯作者：
Sadao Araki;Yasato Kiyohara;S. Tanaka;Yoshikazu Miyake
中科院分区：
文献类型：
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作者：
Sadao Araki;Yasato Kiyohara;S. Tanaka;Yoshikazu Miyake
以18冠-6醚（18C6）为结构导向剂，采用水热法制备了沸石rho，考察了18C6脱除的煅烧温度对沸石理化性能和co2吸附性能的影响。在150℃煅烧的沸石上co2吸附量低于在300℃以上煅烧的沸石。对于300℃以上煅烧的样品，co2吸附随着煅烧温度的增加而增加，最高可达400℃。认为18C6的去除增加了co2的吸附孔体积，从而增加了co2的吸附量。从400°C到500°C，煅烧过程中co2吸附量下降。沸石粒径随18C6摩尔比的增大而增大。通过场发射扫描电镜和动态光散射观察到的颗粒尺寸分别为1.0 ~ 2.1μm和1.4 ~ 2.6μm。通过调节18C6的摩尔比来控制这些区域的粒径。XRD结果表明，18C6摩尔比为0.25 ~ 1.5的沸石样品结晶度较高。无论18C6的摩尔比如何，co2的吸附量几乎是恒定的，为3.4mmol-CO2g−1。CO2选择性（CO2/ n2吸附比）下降。rho分子筛吸附co2的量低于NaX分子筛，但高于SAPO-34分子筛。rho分子筛对CO2/ n2的吸附比高于SAPO-34和NaX分子筛。
Zeolite rho was prepared by hydrothermal synthesis using an 18-crown-6 ether (18C6) as a structure-directing agent, and the effects of the calcination temperature for removal of 18C6 on the physicochemical properties and CO2-adsorption properties were investigated. CO2adsorption on zeolite rho calcined at 150°C was lower than that on samples calcined at temperatures above 300°C. For samples calcined above 300°C, CO2adsorption increased with increasing calcination temperature up to 400°C. It is thought that the pore volume for adsorption of CO2increased as a result of 18C6 removal, resulting in increasing CO2adsorption. A decrease in CO2adsorption for calcination from 400°C to 500°C was observed. The particle size of zeolite rho increased with increasing 18C6 molar ratio. Particle sizes of 1.0–2.1μm and 1.4–2.6μm were found by field-emission scanning electron microscopy and dynamic light-scattering, respectively. The particle size is controlled in these regions by adjusting the 18C6 molar ratio. XRD showed that zeolite rho samples with 18C6 molar ratios of 0.25–1.5 had high crystallinity. The adsorbed amount of CO2is almost constant, at 3.4mmol-CO2g−1, regardless of the 18C6 molar ratio. However, CO2selectivity, which is the CO2/N2adsorption ratio, decreased. The amount of CO2adsorbed on zeolite rho is lower than that on zeolite NaX, but higher than that on SAPO-34. The CO2/N2adsorption ratio for zeolite rho was higher than those for SAPO-34 and zeolite NaX.