In situ Na·Cu3(BTC)2 and Li·Cu3(BTC)2 nanoporous MOFs synthesis for enhancing H2 storage at ambient temperature

Abstract

Na·Cu3(BTC)2 and Li·Cu3(BTC)2 (MOF) were synthesized using in situ sodium and lithium doping as hydrogen adsorbing materials. Phase stability and microstructure of the Na·Cu3(BTC)2 and Li·Cu3(BTC)2 materials were characterized by FT-IR, XRD, SEM, BET, and TGA. After in situ ions doping, the basic structures of Na·Cu3(BTC)2 and Li·Cu3(BTC)2 materials were not changed, but the surface area increased from 1300 to 1434 and 1445 m2 g−1, and the amount of hydrogen adsorbed increased from 1 to 1.4 and 1.6 wt% for Na·Cu3(BTC)2 and Li·Cu3(BTC)2 materials, respectively. Enhancement of hydrogen adsorption after sodium and lithium ion doping could be due to physical interaction (binding energy interaction) between hydrogen molecules and sodium ions and also due to increase of the surface area. It maybe that sodium and lithium ions act as an additional adsorption sites and adsorb hydrogen molecules.