Amino-modified MIL-68(In) with enhanced hydrogen and carbon dioxide sorption enthalpy

The amino modified MIL-68(In), hereafter denoted by MIL-68(In)_NH2, has been obtained by self-assembling from 2-amino-terephthalic acid and indium nitrate hydrate. The characterization of the modified material based on powder X-ray diffraction analysis, IR spectroscopy, H-1 NMR spectroscopy and TG analysis demonstrates that this porous coordination network possesses the Kagome topology of MIL-68(In) with amino modified pores walls. The Brunauer-Emmett-Teller surface area of 1230 +/- 24 m(2) g(-1) for MIL-68(In)_NH2 compared to 1028 +/- 29 m(2) g(-1) for MIL-68(In) exhibits an surface area improvement of approximate 200 m(2) g(-1), within MIL-68(In)_NH2. Moreover, for both hybrids, the hydrogen and carbon dioxide sorption properties have been studied at 77 K and 87 K, and at 273 K and 298 K, respectively. The comparison of the corresponding results of MIL-68(In) shows that the presence of amino group can effectively enhance the adsorption enthalpy of H-2 and CO2 whereas, slightly effect on the integral sorption amount. Besides, to our knowledge, it is the first time that the CO2 adsorption of MIL-68(In) sample are reported. (C) 2011 Elsevier Inc. All rights reserved.