Evaluation of the highly stable metal–organic framework MIL-53(Al)-TDC (TDC = 2,5-thiophenedicarboxylate) as a new and promising adsorbent for heat transformation applications

Abstract

The recently reported Al-based metal–organic framework MIL-53(Al)-TDC (TDC = 2,5-thiophenedicarboxylate) shows desirable water sorption properties towards adsorption-driven heat transformation applications with high thermal and solvent/pH stability as well as hydrothermal stability over 40 cycles. Water vapor sorption measurements at 25, 40 and 60 °C yielded an advantageous isosteric heat of adsorption of only 2.6 kJ g⁻¹, favoring the use of MIL-53(Al)-TDC in sorption based chilling where the released heat of adsorption corresponds to waste heat. The good cooling performance of MIL-53(Al)-TDC comes from desirable low desorption temperatures below 65 °C, with also desirable high condenser temperatures of around 40 °C and corresponding water exchange of almost 0.35 g g⁻¹. The thereby offered working window cannot be provided by common adsorbents and renders the material an ideal candidate for adsorption cooling applications.