High-throughput screening and evaluation of double-linker metal–organic frameworks for CO₂/H₂ adsorption and separation

The capture of CO₂ from CO₂/H₂ gas mixtures in syngas is a crucial issue for hydrogen production from steam methane reforming in industry, as the presence of CO₂ directly affects the purity of H₂. A combination of a high-throughput screening method and grand canonical Monte Carlo simulation was utilized to evaluate and screen 1725 metal–organic frameworks (MOFs) in detail as a means of determining their adsorption performance for CO₂/H₂ gas mixtures. The adsorption and separation performance of double-linker MOFs was comprehensively evaluated using eight evaluation indicators, namely, the largest cavity diameter, accessible surface area, pore occupied accessible volume, porosity, adsorption selectivity, working capacity, adsorbent performance score and percent regeneration. Six optimal performance frameworks were screened to further study their single-component adsorption and binary competitive adsorption of CO₂/H₂ respectively. The CO₂ adsorption selectivity at different CO₂/H₂ feed ratios was also evaluated, which indicated their excellent adsorption and separation performance. The microscopic adsorption mechanisms for CO₂ and H₂ at the molecular level were investigated by analyzing the radial distribution function and density distribution. This study may provide directional guidance and reference for subsequent experiments on the adsorption and separation of CO₂/H₂.