抄録
We investigate the adsorption of D2/H2 and HD/H2 binary mixtures in carbon slit pores and carbon cylindrical pores using equilibrium molecular simulations, and determine the optimum pore size and topology for the quantum sieving of hydrogen isotopes at 77 K. We show that the grand canonical Monte Carlo method with the Feynman–Hibbs variational approach (FH-GCMC) can be used as an alternative to that with the rigorous Feynman path-integral formalism (PI-GCMC) for exploring quantum H2 adsorption at 77 K. Further, we employ FH-GCMC to investigate the adsorption of D2/H2 and HD/H2 binary mixtures at 77 K. We show that, under the separation conditions of adsorption/desorption cycling between 0.1 and 1 MPa at 77 K, the optimum pore topology for quantum sieving of hydrogen isotopes is a cylindrical pore, and the pore sizes that yield the largest recoverable adsorption amounts with high selectivity are 0.623 nm for D2 and 0.625 nm for HD. We also demonstrate, by comparing the results with those from the binary-mixture FH-GCMC simulations, that the ideal adsorbed solution theory can effectively predict the selectivity of D2 and HD over H2 in nanopores at 77 K (below 1 MPa).
