Tuning fluorocarbon adsorption in new isoreticular porous coordination frameworks for heat transformation applications.

Adsorption heat transformation is one of the most energy-efficient technologies, which relies much on the type and performance of the adsorbent-adsorbate pair. Here, we report adsorption behaviors of a typical fluorocarbon R22 (CHClF) in a new series of isoreticular porous coordination polymers [ZnO(bpz)(ldc)], in which the typical ZnO clusters are connected by hydrophobic 3,3',5,5'-tetramethyl-4,4'-bipyrazolate (bpz) and different linear dicarboxylates (ldc) to form non-interpenetrated networks with variable pore sizes, shapes, and volumes. Fluorocarbon sorption measurements of these materials revealed high R22 uptakes of 0.73-0.97 g g (0.62-0.65 g cm) at 298 K and 1 bar and working capacities of 0.41-0.72 g g (0.35-0.47 g cm) between 273 and 313 K at about 0.13, 0.11 and 0.52 bar, respectively, as well as very large diffusion coefficients of 5.1-7.3 × 10 cm s. Noteworthily, the R22 sorption performance can be dramatically improved by subtle modification of the pore size and shape, demonstrating porous coordination polymer-fluorocarbon as a promising adsorbent-adsorbate pair for heat transformation applications.