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

[Image: see text] 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.