(223z) Structure-Transport Relationship for Confined Fluids: The Example of CO2 and n-Butane in Silica Pores

Competitive adsorption was investigated for the mixture of carbon dioxide and n-butane in microporous hydroxylated silica pores using Molecular Dynamics simulations. The effects of temperature, pressure and composition on the mobility of each species were studied. Preferential adsorption of carbon dioxide near the protonated –OH groups on the surface was observed, which explains slow self-diffusion coefficients at low loadings. The results can be useful for long-term CO₂ capture strategies and separation processes. The results are compared to available experimental data, and the implications for practical applications are discussed.