Bimodal activated carbons derived from resorcinol-formaldehyde cryogels
Bimodal activated carbons derived from resorcinol-formaldehyde cryogels
复制标题
由间苯二酚-甲醛冷冻凝胶衍生的双峰活性炭
DOI：
10.1088/1468-6996/12/3/035001
复制
发表时间：
2011
影响因子：
5.5
通讯作者：
A. Celzard
中科院分区：
文献类型：
--
作者：
A. Szczurek;G. Amaral;V. Fierro;A. Pizzi;A. Celzard
摘要在450 °C下用磷酸活化不同稀释比制备的间苯二酚-甲醛冻凝胶，并与900 °C下热解得到的碳质冻凝胶进行了比较。而后者，如预期的那样，高度介孔碳，前冻凝胶有非常不同的孔纹理。高度稀释的冷冻凝胶允许制备具有高表面积的微孔材料，但是初始致密冷冻凝胶的活化导致几乎无孔的碳，其表面积比通过热解获得的那些低得多。用于活化的最佳酸浓度（对应于酸和羟基分子之间的化学计量）为2 M l-1，并且酸-晶胶接触时间也具有最佳值。这样的优化使我们能够实现有史以来通过H3 PO 4活化获得的最高表面积和体积，分别接近2200 m2 g−1和0.7 cm 3 g−1。用1.2 M l-1的较低酸浓度活化稀释的冻凝胶，得到真正的双峰活性炭，其表面积高达1780 m2 g-1，微孔体积为0.6 cm 3 g-1，通过广泛开发的大孔隙度容易获得。
Abstract Resorcinol-formaldehyde cryogels prepared at different dilution ratios have been activated with phosphoric acid at 450 °C and compared with their carbonaceous counterparts obtained by pyrolysis at 900 °C. Whereas the latter were, as expected, highly mesoporous carbons, the former cryogels had very different pore textures. Highly diluted cryogels allowed preparation of microporous materials with high surface areas, but activation of initially dense cryogels led to almost non-porous carbons, with much lower surface areas than those obtained by pyrolysis. The optimal acid concentration for activation, corresponding to stoichiometry between molecules of acid and hydroxyl groups, was 2 M l−1, and the acid–cryogel contact time also had an optimal value. Such optimization allowed us to achieve surface areas and micropore volumes among the highest ever obtained by activation with H3PO4, close to 2200 m2 g−1 and 0.7 cm3 g−1, respectively. Activation of diluted cryogels with a lower acid concentration of 1.2 M l−1 led to authentic bimodal activated carbons, having a surface area as high as 1780 m2 g−1 and 0.6 cm3 g−1 of microporous volume easily accessible through a widely developed macroporosity.
影响因子：
10.9
作者：
H. Nishihara;S. Mukai;H. Tamon
通讯作者：
H. Nishihara;S. Mukai;H. Tamon