Metal Organic Frameworks (MOFs) have been proposed for use in the separation of molecules or materials from mixtures.  Gas phase molecules are readily adsorbed into MOFs but then need to be reliably released when desired.  Cycling between oxidation states of the metal centers in the MOF provides a convenient method for this.  One especially valuable application is, for example, cycling a working fluid for thermal assemblies.

Thus, a refrigerant is adsorbed onto a bed containing the MOF at low pressure. An electrical potential is then used to change the oxidation state of the metal center, releasing (desorbing) the refrigerant.  Desorption raises the pressure and temperature of the refrigerant, which can then pass through an expansion valve to adiabatically cool the working fluid.  Once cooled, it is now available to pass through an evaporator to absorb heat, completing the refrigeration cycle.