The dependence of the hydrogen sorption capacity of single-walled carbon nanotubes on the concentration of catalyst

Autor:	D.K. Ross, D. J. Riley, Ian Morrison, Majid Seifi
Rok vydání:	2009
Předmět:	Langmuir Hydrogen Chemistry Binding energy Analytical chemistry Langmuir adsorption model chemistry.chemical_element General Chemistry Carbon nanotube Catalysis law.invention symbols.namesake Adsorption law symbols medicine Physical chemistry General Materials Science Activated carbon medicine.drug
Zdroj:	Carbon. 47:3184-3191
ISSN:	0008-6223
DOI:	10.1016/j.carbon.2009.07.030
Popis:	The adsorption of hydrogen on single-walled carbon nanotubes was measured using micro-gravimetric nitrogen and hydrogen adsorption isotherms at 77 K for gas pressures of up to 1 bar (nitrogen) and 12 bar (hydrogen). Results show that surface area and hydrogen uptake depend on the concentration of the iron catalyst used for making the nanotubes. Langmuir fits to the hydrogen uptake curves clearly show two adsorption energies for each sample which we attribute to the groove site for the higher adsorption energy and to the convex tube surface for the lower energy. We also present calculations of the binding energy of hydrogen on these same sites on SWCNTs and confirm that the groove site has a significantly higher (radius-dependent) binding energy than the surface site, consistent with the experimental values. This suggests that the use of the Langmuir model is appropriate to the adsorption of H2 on activated carbons for the temperature and pressure range investigated and could be used as a rapid way of estimating the average tube radius in the sample.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_________::26457933e0332841f09446240b71c0f4 https://doi.org/10.1016/j.carbon.2009.07.030 Zobrazit plný text záznamu Full Text from ScienceDirect