Hydrogen adsorption on activated carbons prepared from olive waste: effect of activation conditions on uptakes and adsorption energies

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• 作者：Redouane Melouki ; Philip L. Llewellyn ; Sana Tazibet…
• 关键词：Activated carbon ; Hydrogen ; Adsorption ; Heat treatment ; Calorimetry
• 刊名：Journal of Porous Materials
• 出版年：2017
• 出版时间：February 2017
• 年：2017
• 卷：24
• 期：1
• 页码：1-11
• 全文大小：
• 刊物类别：Chemistry and Materials Science
• 刊物主题：Catalysis; Characterization and Evaluation of Materials; Physical Chemistry;
• 出版者：Springer US
• ISSN：1573-4854
• 卷排序：24

文摘

Two series of activated carbon samples have been prepared from olive waste, using ZnCl₂ and H₃PO₄ as chemical activation agents. The porous structure characteristics of all samples are determined by nitrogen adsorption at −196 °C. Hydrogen adsorption at −196 °C is followed using both manometry and calorimetry. The results show that the highest areas are observed for the samples prepared with larger diameter of precursors and that the hydrogen uptake is strongly influenced by the available BET area. Furthermore, the adsorption energies do not vary significantly for any activation protocol and therefore seem to play only a minor role to the hydrogen adsorption behavior. However, the chemical activation does have a strong role on hydrogen uptake. Samples prepared with H₃PO₄ show a greater hydrogen uptake per unit area such that comparable uptakes are observed for the samples prepared with larger diameter of precursor even though the sample prepared with ZnCl₂ shows a 30 % higher BET area. This work highlights the non-trivial role of each activation protocol on hydrogen uptake.