Modification of the porous structure along the preparation of activated carbon monoliths with H3PO4 and ZnCl2
Modification of the porous structure along the preparation of activated carbon monoliths with H3PO4 and ZnCl2
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DOI：
10.1016/j.micromeso.2007.01.029
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发表时间：
2007-06-20
影响因子：
5.2
通讯作者：
Rodriguez-Reinoso, F.
中科院分区：
文献类型：
--
作者：
Nakagawa, Y.;Molina-Sabio, M.;Rodriguez-Reinoso, F.
在不使用任何粘合剂的情况下，用磷酸或氯化锌对橄榄石进行化学活化，制备了两个系列的活性炭单体（圆盘）。介绍了化学浸渍与热处理之间的协调步骤。制备了两个等效系列的颗粒活性炭，分析了定型压力对最终活性炭孔隙率的影响。采用气体吸附法（-196℃下的N-2和0℃下的CO2）和浸没量热法对三种不同分子尺寸的液体（二氯甲烷、苯和2,2-二甲基丁烷）进行了微孔演化和微孔尺寸分布。实验结果表明，两种化学物质的活化都使微孔发育，但在磷酸的作用下，颗粒状和整体状微孔的差异更为明显。因此，在使用氯化锌制备的圆盘形成过程中，主要是颗粒间空间和宏观孔隙度的减少，而在使用磷酸时，中孔和微孔的体积和尺寸也有额外的减少。这两种化学物质的不同行为与它们在浸渍过程中对前驱体的影响有关。(C) 2007爱思唯尔公司版权所有。
Two series of activated carbon monoliths (discs) have been prepared by chemical activation of olive stones with phosphoric acid or zinc chloride, without the use of any binder. A conforming step was introduced between impregnation with the chemical and heat treatment. Two equivalent series of granular activated carbons were also prepared in order to analyse the effect of conforming pressure on the porosity of the final activated carbon. The evolution of microporosity and the micropore size distribution has been followed by gas adsorption (N-2 at -196 degrees C and CO2 at 0 degrees C) and immersion calorimetry into three liquids with different molecular dimensions (dichloromethane, benzene and 2,2-dimethylbutane).The experimental results indicate that activation by both chemicals produces a large development of microporosity but the differences between the granular and monolithic forms are more noticeable when using phosphoric acid. Thus, there is mainly a reduction in the interparticle space and macroporosity during the formation of the discs prepared using zinc chloride whereas there is an additional reduction in the volume and dimension of the meso- and microporosity when using phosphoric acid. The different behaviour of the two chemicals has been related to their effect on the precursor along the impregnation step. (C) 2007 Elsevier Inc. All rights reserved.