"Nanotechnology and nanomaterials"

Microporous organic polymers as room temperature 
hydrogen storage materials
Saldan I., Stetsiv Y., Makogon V., Kovalyshyn Y., 
Yatstyshyn M., Reshetnyak O.
Department of Physical and Colloid Chemistry, Ivan Franko National University of Lviv. Kyryla and Mefodia St. 6, 79005-Lviv, Ukraine
E-mail: saldanivan@gmail.com

Physical sorption of gases, dominated by the interplay between the values of surface area, changes in entropy and enthalpy might be a promising task. However, substantial amounts of hydrogen can be adsorbed only by micropores at about 2-3 nm. The main advantages of organic polymers as compared to other porous materials are as follows: i) the possibility to use different reactions for their synthesis; ii) their insensitivity to ambient air; and iii) their mechanical stability as compared to porous carbons and metal-organic frameworks.
In the overwhelming majority of materials, only micropores enable to adsorb substantial amounts of molecular hydrogen because of high value of active surface area (~4000-4500 m2/g). Today the hydrogen storage capacity at room temperature and Р(Н2) 20 MPa for microporous organic polymers reaches the values typical for interstitial metal hydrides, e.g. Ti- or Zr-based alloys, at Р(Н2) 0.2-0.5 MPa, that were recommended for reversible electrochemical hydrogen reaction in Ni-MH batteries [1,2]. However, only at lower temperatures (77 K) and Р(Н2) 20 MPa physical adsorption by microporous organic polymers demonstrates hydrogen storage capacity within the range of 6-7 wt.% H2 that becomes reasonable for fuel cell application [3]. Moreover, hydrogen-saturated polymers usually show complete hydrogen desorption with fast kinetics at ambient temperatures, that makes them fully reversible. The present work describes crosslinked and hypercrosslinked polymers viewed as high surface area materials to adsorb a large amount of molecular hydrogen.

1.	Saldan I., Burtovyy R., BeckerH.-W., AderV., Wöll Ch. Ti-Ni alloys as MH electrodes in Ni-MH accumulators // Int J Hydrogen Energy.- 2008.-33.-P. 7177-7184.
2.	Saldan I. Primary estimation of metal hydride electrode performance // J Sol State Electrochem.- 2010.-14.-P. 1339-1350.
3.	Saldan I., Stetsiv Y., Makogon V., Kovalyshyn Y., Yatsyshyn M., Reshetnyak O. Physical sorption of molecular hydrogen by microporous organic polymers // Chem Chem Tech. - 2018. In print.