Freundlich, Langmuir, Temkin and Harkins-Jura Isotherms Studies of H2 Adsorption on Porous Adsorbents

Fatma Oguz Erdogan
2019 Chemistry & Chemical Technology  
1 The hydrogen adsorption and desorption isotherms of multiwalled carbon nanotube sample (MWCNT), an iron loaded multiwalled carbon nanotube (Fe_MWCNT), two zeolites (Na_Y_Zeo and NH4_Y_Zeo) and MCM-41 were measured at 77 K and atmospheric pressure by using the volumetric adsorption apparatus. The adsorption data were evaluated by several isotherm equations such as Langmuir, Freundlich, Temkin and Harkins-Jura isotherm models but were best described by the Freundlich isotherm model as it gave
more » ... model as it gave the highest correlation. The amount of adsorbed hydrogen by weight depended on the micropore volume of the sample, except for MWCNT and Fe_MWCNT. The porous samples were characterized by scanning electron microscopy (SEM) and N 2 adsorption isotherms. The maximum hydrogen storage of 1.96 wt % at 77 K was achieved by Fe_MWCNT. Microporous Na_Y_Zeo and NH 4 _Y_Zeo showed higher hydrogen adsorption capacities than the mesoporous MCM-41. The hydrogen adsorption properties of these porous adsorbents may be further enhanced by different metal doping, thus paving the way for further study. Keywords: hydrogen adsorption capacity, multiwalled carbon nanotube, zeolite, MCM-41, iron multiwalled carbon nanotube composite.
doi:10.23939/chcht13.02.129 fatcat:r56wsgucmncdtlfofwzr5zaak4