Quantum sieving effect of three-dimensional Cu-based organic framework for H2 and D2

J Am Chem Soc. 2008 May 21;130(20):6367-72. doi: 10.1021/ja077469f. Epub 2008 Apr 30.

Abstract

The crystal structure of [Cu(4,4'-bipyridine) 2(CF 3SO 3) 2] n metal-organic framework (CuBOTf) of one-dimensional pore networks after pre-evacuation at 383 K was determined with synchrotron X-ray powder diffraction measurement. Effective nanoporosity of the pre-evacuated CuBOTf was determined with N 2 adsorption at 77 K. The experimental H 2 and D 2 adsorption isotherms of CuBOTf at 40 and 77 K were measured and then compared with GCMC-simulated isotherms using the effective nanoporosity. The quantum-simulated H 2 and D 2 isotherms at 77 K using the Feynman-Hibbs effective potential coincided with the experimental ones, giving a direct evidence on the quantum molecular sieving effect for adsorption of H 2 and D 2 on CuBOTf. However, the selectivity for the 1:1 mixed gas of H 2 and D 2 was 1.2. On the contrary, experimental H 2 and D 2 isotherms at 40 K had an explicit adsorption hysteresis, originating from the marked pore blocking effect on measuring the adsorption branch. The blocking effect for quantum H 2 is more prominent than that for quantum D 2; the selectivity for D 2 over H 2 at 40 K was in the range of 2.6 to 5.8. The possibility of the quantum molecular sieving effect for H 2 and D 2 adsorption on [Cu 3(benzene-1,3,5-tricarboxylate) 2(H 2O) 3] n of three-dimensional pore networks was also shown at 77 K.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adsorption
  • Benzene Derivatives / chemistry
  • Chromatography, Gel
  • Copper / chemistry*
  • Deuterium / chemistry*
  • Hydrogen / chemistry*
  • Models, Molecular
  • Monte Carlo Method
  • Organometallic Compounds / chemistry*
  • Pyridines / chemistry
  • Quantum Theory
  • Thermodynamics
  • X-Ray Diffraction

Substances

  • Benzene Derivatives
  • Organometallic Compounds
  • Pyridines
  • Copper
  • Hydrogen
  • Deuterium
  • 4,4'-bipyridyl