Hydrogen adsorption on Ag+, Ca2+and Ni2+exchanged chabazite: Influence of ammonium nitrate pretreatment and calcination

The practical application of hydrogen in daily life as a daily energy source, in competition with fossil fuels, is dependent upon the overcoming of the technical challenges associated with the storage of this energy. Although a considerable number of studies have been conducted on the storage of hydrogen in porous synthetic materials, including MOFs and carbon-based structures, there are fewer studies utilizing natural zeolites for the same purpose. In this study, the usability of natural chabazite (Raw-CHA) from Bala (T & uuml;rkiye) for hydrogen storage was investigated. Firstly, the H+ form of Raw-CHA was obtained by modification with 1.0 M NH4NO3 solutions at 80 degrees C for 4 h, followed by calcination at 400 degrees C for 5 h. Secondly, the H+ form was treated with different concentrations (0.05, 0.15, 0.25 and 0.50 M) of AgNO3, Ca(NO3)2.4H2O and Ni(NO3)2.6H2O solutions at 80 degrees C for 4 h to evaluate the effect of ion exchange with different cations on hydrogen adsorption. The samples were characterized by X-ray diffraction (XRD), X-ray fluorescence (XRF), energy dispersive X-ray spectroscopy (EDS) and nitrogen adsorption methods. The hydrogen adsorption capacities of all the samples at 77 K exhibited a range of 0.818-1.080 wt%.