Overcoming the Trade-Off between C2H2 Sorption and Separation Performance by Regulating Metal-Alkyne Chemical Interaction in Metal-Organic Frameworks

Designing porous materials for C2H2 purification and safe storage is essential research for industrial utilization. We emphatically regulate the metal-alkyne interaction of Pd-II and Pt-II on C2H2 sorption and C2H2/CO2 separation in two isostructural NbO metal-organic frameworks (MOFs), Pd/Cu-PDA and Pt/Cu-PDA. The experimental investigations and systematic theoretical calculations reveal that Pd-II in Pd/Cu-PDA undergoes spontaneous chemical reaction with C2H2, leading to irreversible structural collapse and loss of C2H2/CO2 sorption and separation. Contrarily, Pt-II in Pt/Cu-PDA shows strong di-sigma bond interaction with C2H2 to form specific pi-complexation, contributing to high C2H2 capture (28.7 cm(3) g(-1) at 0.01 bar and 153 cm(3) g(-1) at 1 bar). The reusable Pt/Cu-PDA efficiently separates C2H2 from C2H2/CO2 mixtures with satisfying selectivity and C2H2 capacity (37 min g(-1)). This research provides valuable insight into designing high-performance MOFs for gas sorption and separation.

Automated summary

Designing porous materials that can purify and safely store C2H2 is crucial for industrial usage. We examined the metal-alkyne interaction of Pd-II and Pt-II on C2H2 sorption and separation in two isostructural NbO metal-organic frameworks (MOFs), Pd/Cu-PDA and Pt/Cu-PDA. The results showed that Pd-II undergoes a spontaneous chemical reaction with C2H2, leading to structural collapse and loss of C2H2/CO2 sorption and separation. Conversely, Pt-II forms a strong di-sigma bond with C2H2, resulting in high C2H2 capture. The reusable Pt/Cu-PDA efficiently separates C2H2 from C2H2/CO2 mixtures with satisfying selectivity and C2H2 capacity. This research provides valuable insights for designing high-performance MOFs for gas sorption and separation.