The distillation of light gases requires significant energy inputs. Sorbents could alleviate this issue, but they must be able to separate molecules of similar size and chemical functionality. Here, we report the enhanced separations of gases such as propane and propylene using zeolite 5A modified with phosphonic acids (PAs) of varying alkyl tail length. All PAs slow the diffusion of n-C₄H₁₀ but generally have a smaller effect on the diffusion rate and loading of smaller molecules such as CO₂ and CH₄. However, methylphosphonic acid (C₁PA) decreases by >90% both the diffusion rates and apparent equilibrium uptakes of n-C₄H₁₀ and C₃H₆. The achievable loadings of C₃H₆, C₂H₆, CH₄, and CO₂ are affected much less, resulting in a C₃H₆-C₃H₈ ideal selectivity of 59 ± 14. The unique effects of C₁PA are correlated to a much higher extent of deposition near the zeolite surface, while longer-chain PAs are confined to a monolayer on the external surface.

轻质气体的蒸馏需要大量的能量输入。吸收剂可以缓解这个问题，但是它们必须能够分离大小和化学功能相似的分子。在这里，我们报道了使用5A分子筛烷基末端长度的膦酸（PAs）改性的5A沸石增强了丙烷和丙烯等气体的分离。所有PA都会减慢n -C ₄ H ₁₀的扩散，但通常对较小分子（如CO ₂和CH _4）的扩散速率和负载量影响较小。但是，甲基膦酸（C ₁ PA）的扩散速率和n -C ₄ H的表观平衡吸收均降低> 90％₁₀和C ₃ H ₆。C的可实现的负载₃ ħ ₆，C ₂ H ^ ₆，CH ₄和CO ₂的少得多的影响，导致在C ₃ H ^ ₆ -C ₃ ħ ₈的59种±14的独特的效果理想选择性Ç ₁ PA与沸石表面附近更高的沉积程度相关，而长链PA则限于外表面上的单层。