A stable metal–organic framework with well‐matched pore cavity for efficient acetylene separation

Abstract

Acetylene, an important petrochemical feedstock, is the starting chemical to produce many polymer products. Separating C2H2 from its by‐product mixtures is still an energy‐consuming process and remains challenging. Here, we present a metal–organic framework[Zn2(bpy)(btec)], with a desirable pore geometry and stable framework, which demonstrated a high separation performance of C2H2 from simulated mixtures. With the desirable pore dimension and hydrogen bonding sites, Zn2(bpy)(btec) shows by far the both highest C2H2/C2H4 and C2H2/CO2 uptake ratios, very high adsorption selectivities and moderately C2H2 uptake of 93.5 cm3/cm3 under 298 K and 1 atm. Not only straightforwardly produced high purity of C2H4, but also recovered high purity of C2H2 (>98%) in the regeneration process (>92% recovery). More notably, Zn2(bpy)(btec) can be straightforwardly synthesized at a large scale under environmentally friendly conditions, and its good water/chemical stability, thermostability, and cyclic stability highlight the promise of this molecular sieving material for industrial C2H2 separation.

Efficient C2H2/CO2 Separation in Ultramicroporous Metal–Organic Frameworks with Record C2H2 Storage Density

“…A major driving force behind the recent explosion of interest in MOFs lies with their amenability to design using the reticular principle, which is unattainable for traditional porous materials. − In particular, with respect to gas separation, crystal engineering of MOFs enables ultrafine control over pore size/shape and surface environment to realize enhanced or even sieving separation . Specifically, for C 2 H 2 /CO 2 separation, since Kitagawa and co-workers for the first time introduced the prototypal C 2 H 2 selective sorbent in 2005, there has been little progress in this domain, and only a handful of MOFs out of 70,000+ total have been reported to be effective. − Until very recently, there is a striking upsurge in developing highly efficient C 2 H 2 selective MOF sorbents, ,,− ,,− achieving the highest known C 2 H 2 /CO 2 (50:50) separation selectivity of 185 . However, dominating these C 2 H 2 sorbents of MOFs are those designed with multiple open metal sites (OMSs) that can significantly enhance the binding affinity with C 2 H 2 and thus boost selectivity.…”

A Microporous Titanate‐Based Metal‐Organic Framework for Efficient Separation of Acetylene from Carbon Dioxide

“…Since the two gas molecules have the same molecular size/shape (3.3 Å for both C 2 H 2 and CO 2 ), fine tuning of pore size or flexibility on MOFs is quite limited to achieve high separation performance. In this context, the most popular strategy is to introduce strong binding sites, such as open metal sites [25][26][27][28][29] or functional groups (e. g., NH 2 , SiF 6 2À , CN) [30][31][32][33][34][35][36][37][38][39][40][41][42][43][44][45][46][47] onto the pores to enforce the binding affinity for C 2 H 2 . However, there commonly exists a trade-off between selectivity and gas uptake.…”

Improving CH4 uptake and CH4/N2 separation in pillar‐layered metal–organic frameworks using a regulating strategy of interlayer channels

“…The breakthrough curves for binary CH 4 /N 2 (50/50, v/v) mixtures were collected at a flow rate of 5 ml/min (298 K, 1 bar) using a self‐made separation device 40 . In the separation experiments, Ni(BTC)(BPY) (1.14 g), Ni(BTC)(TED) (1.15 g), and Ni(BTC)(PIZ) (1.17 g) samples were packed into a Φ 4 mm × 100 mm stainless steel columns, and the columns were activated under vacuum at 150°C overnight.…”