Quantum Sieving Effect of Modified Activated Carbon Fibers on H₂ and D₂ Adsorption at 20 K

Abstract

Quantum sieving of activated carbon fibers (ACFs) and their fluorides was observed for H(2) and D(2) adsorption at 20 K. Fluorination reduced the slit-shaped pore width of ACFs by 0.2 nm. The activated carbon fibers can act as highly efficient quantum sieves for H(2) and D(2), because the effective size of an H(2) molecule is larger than that of a D(2) molecule due to the uncertainty principle and the molecular size difference between H(2) and D(2) is significant in the micropore space. The D(2)/H(2) selectivity of ACFs evaluated by ideal adsorption solution theory was larger than that of the fluorinated ACFs.

Quantum sieving: feasibility and challenges for the separation of hydrogen isotopes in nanoporous materials

“…Noguchi et al 40 also used IAST to evaluate the D 2 /H 2 selectivity in CuBOTf, showing values around 1.3 at 77 K over a whole range of pressure while in the range 1.9 y 3.0 kPa at 40 K and increases with pressure. Hattori et al 49 used IAST to evaluate the effects of fluorination on the selectivity of activated carbon fibers (ACF) at 20 K. The results show that the selectivity both in ACFs and F-ACFs increases monotonically with pressure, though the selectivity in ACFs is always larger than the one in F-ACFs. Tanaka et al 41 analyzed the D 2 /H 2 selectivity by the IAST in (10, 10) interstices at 77 K (Fig.…”

Boltzmann bias grand canonical Monte Carlo

“…3,4,7,8,9,10,11,12,13,14 Recently the first experimental confirmations have been reported. 15,16 From a simulation point of view the PIMC method maps the statistical mechanics of N quantum particles into the statistical mechanics of N ring polymers, each formed by P particles. The mapping is exact in the limit P → ∞, even though, according to the temperature investigated, convergence of the results can be obtained when P is of the order of 10-100.…”

Photocatalysis, microstructure, and surface characterization of TiO2‐loaded wooden‐activated carbon fibers

“…b–d. Figure b shows that the C1s curve fitting is optimized into three independent peaks: the graphitic carbon (CC, binding energy [BE] = 284.3–284.6 eV), ether or hydroxy group (CO, BE = 285.5–285.8 eV), and carbonyl or quinine groups (CO, BE = 286.3–286.7 eV) , respectively. It is clear that the loaded nano‐TiO 2 s do not affect the formation of graphite structure of WACFs.…”