Nano-CaCO3 as template for preparation of disordered large mesoporous carbon with hierarchical porosities
Nano-CaCO3 as template for preparation of disordered large mesoporous carbon with hierarchical porosities
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DOI：
10.1039/b911913b
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发表时间：
2010-01
影响因子：
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通讯作者：
Chun-Mei Zhao;Wei-kun Wang;Zhongbao Yu;Hao Zhang;An-bang Wang;Yusheng Yang
中科院分区：
文献类型：
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作者：
Chun-Mei Zhao;Wei-kun Wang;Zhongbao Yu;Hao Zhang;An-bang Wang;Yusheng Yang
以市售纳米碳酸钙为模板剂，甲醛树脂为碳前驱体，用盐酸溶液去除模板剂，制备了一系列具有层次化孔道的大分子介孔碳(LMC，20-50 nm)。在炭化过程中，CaCO3模板剂分解释放出的CO2起到活化剂的作用，活化产生微孔和中孔的炭材料，并扩大孔径。通过比较在900℃(高于CaCO3的热解温度)和650℃(低于CaCO3的热解温度)两个临界温度下炭化后的炭化产物的产碳率、氮气吸附/脱附等温线、孔径分布和质构参数，证明了这种效应是“CO2内活化效应”。结果表明，在不同CaCO_3/PF比例下制备的LMC样品的比表面积为503~1215m2g−1，孔容为1.80~9.0cm3g−1。这种具有CO_2内活化效应的一步炭化方法为制备大孔炭和多孔炭材料提供了一条新的途径。
A series of large mesoporous carbons (LMC, 20–50 nm) with hierarchical porosities has been prepared using commercially available CaCO3 nanoparticles as a template, formaldehyde (PF) resin as carbon precursor, and HCl solution for removing the template. During the carbonization process, the CaCO3 template decomposes releasing CO2 which serves as an activating agent to active the carbon materials producing micropores and mesopores as well as enlarging pore sizes. This effect can be named as the “CO2 inner-activation effect”, which is proved by comparing the carbon yield, N2 adsorption/desorption isotherms, pore-size distribution and textual parameters of carbon materials carbonized at two critical temperatures, namely, 900 °C (higher than the pyrolysis temperature of CaCO3) and 650 °C (lower than the pyrolysis temperature of CaCO3). Our results show that the LMC samples prepared at different ratios of CaCO3 to PF have BET surface areas ranging from 503 to 1215 m2 g−1, and pore volumes ranging from 1.8 to 9.0 cm3 g−1. This one-step carbonization method with a CO2 inner-activation effect provides a novel route to prepare large mesoporous carbons and hierarchical porous carbon materials.