MFM-300 as High-Performance Sorbents for Water-Adsorption-Driven Cooling

Adsorption-driven heat transfer is potentially a sustainable technology to decarbonize heating and cooling. However, the development of high-performance adsorbent-adsorbate working pairs remains extremely challenging. Here, we report a metal-organic framework/water working pair that can operate at an ultralow driving temperature (62 °C), showing a high coefficient of performance (COP) of 0.8 for cooling. The desirable features of MFM-300(M) (M = Al, Fe, Cr, V) for water adsorption have been elucidated by combined crystallographic and spectroscopic techniques. In situ neutron powder diffraction reveals the structural evolution of the MFM-300-D₂O system via direct observation of the location of D₂O at different stages of adsorption. Host-guest binding dynamics have been interrogated by in situ solid-state nuclear magnetic resonance spectroscopy and inelastic neutron scattering combined with modeling. This system promotes the use of renewable low-grade thermal energy rather than electricity to drive cooling.