The MIL-125 Metal–Organic Framework Structure for Adsorption-Based Accumulation of Methane and Hydrogen.

A MIL-125 metal–organic framework structure was synthesized from titanium and 1, 4-benzenedicarboxylic acid. The specific micropore volume of the synthesized sample was found to be W₀ = 0.59 cm³/g, and the specific BET surface area was S_BET = 1320 m²/g. Analysis of the synthesized material revealed the possibility of its application for accumulating energetically important gases: methane and hydrogen. The adsorption of hydrogen and methane on MIL-125 was experimentally studied within the temperature range of 77−293 K for hydrogen and 213−293 K for methane at absolute pressures up to 1.5 bar. The high heats of methane and hydrogen adsorption on the synthesized sample of about 26 and 14 kJ/mol were evaluated. It was found that, due to narrow pores, the adsorbent may be effective in accumulating methane at high temperatures. MIL-125 exhibited the best adsorption performance for hydrogen. At the temperature of 77 K and atmospheric pressure, the sample can accumulate up to 2.3 wt % hydrogen. [ABSTRACT FROM AUTHOR]