High Working Capacity Acetylene Storage at Ambient Temperature Enabled by a Switching Adsorbent Layered Material

Abstract

Unlike most gases, acetylene storage is a challenge because of its inherent pressure sensitivity. Herein, a square lattice ( sql ) coordination network [Cu(4,4′-bipyridine) 2 (BF 4 ) 2 ] n ( sql-1-Cu-BF 4 ) is investigated with respect to its C 2 H 2 sorption behavior from 189 to 298 K. The C 2 H 2 sorption studies revealed that sql-1-Cu-BF 4 exhibits multistep isotherms that are temperature-dependent and consistent with the transformation from “closed” (nonporous) to four “open” (porous) phases induced by the C 2 H 2 uptake. The Clausius–Clapeyron equation was used to calculate the performance of sql-1-Cu-BF 4 for C 2 H 2 storage at pressures >1 bar, which revealed that its volumetric working capacity at 288 K is slightly superior to acetone (174 vs 170 cm 3 cm –3 ) over a safer pressure range (1–3.5 vs 1–15 bar). Molecular simulations provided insights into the observed switching phenomena, revealing that the layer expansion of sql-1-Cu-BF 4 occurs via intercalation and inclusion of C 2 H 2 . These results indicate that switching adsorbent layered materials offer promise for utility in the context of C 2 H 2 storage and delivery.

Pressure-Induced Structural Effects in the Square Lattice (sql) Topology Coordination Network Sql-1-Co-NCS·4OX

“…22,30 Indeed, out of the all xylene loaded sql-1-Co-NCS crystals, only for the OX-loaded phase was a one-step desorption noted. 22 That the pressure-induced desorption of sql-1-Co-NCS•xOX proceeded via at least two partially loaded intermediate phases resembles ELM-11, which exhibited multistep CO 2 and C 2 H 2 sorption isotherms at 195 K. 28 Increased pressure also affected the conformation of 4,4′bipyridine ligands. The angle between the pyridine rings of the ligands and the sql plane decreased at 1.04 GPa, dropping below 70°(Table S4).…”

New Paradigms in Porous Framework Materials for Acetylene Storage and Separation

“…Furthermore, the material had a slightly superior working capacity at 288 K over a safer pressure range (1-3.5 vs 1-15 bar). [14] Another promising strategy for tuning the binding sites to bring about more efficient interactions and better acetylene capture is the pore space partition (PSP) that as the name suggests, partitions the pore space of MOFs into multiple domains by the use of partitioning agents (PPAs). Wang et al utilized this PSP strategy to partition the MIL-88 type acs frameworks via in situ generated 4,4'-dipyridylsulfide (dps) ligands, leading to partitioned acs (pacs) crystalline porous materials (CPM) shown in Figure 6.…”

Adsorbate-dependent phase switching in the square lattice topology coordination network [Ni(4,4′-bipyridine)2(NCS)2]n

“…1a) when triggered by gases such as N 2 , O 2 , Ar, CO 2 and C 2 H 2 . [33][34][35] Recently, we studied the sorption properties of three previously known sql CNs [M(bpy) 2 (NCS) 2 ] (M = Fe, Co, or Ni), [36][37][38][39] sql-1-M-NCS, which are isostructural to the ELM family. Their CO 2 sorption isotherms under low or high temperatures/pressures were observed to exhibit single-step type F-IV isotherms and the switching pressures were found to be metal-ion controlled.…”