The adsorption/desorption of up to 0.75 g of water vapour per g of the porous MOFs 3D-{M 3 O(X)(H 2 O) 2 [btc] 2 $nH 2 O}, MIL-100 (M ¼ Al, Fe; X ¼ OH, F, btc ¼ benzene-1,3,5-tricarboxylate, trimesate), occurs at small relative pressures of p/p 0 < 0.4 and a comparatively small hysteresis. Together with very good cycle stability, these properties render both MIL-100(Al and Fe) very suitable candidates for thermally driven heat pumps or adsorption chillers.More than 50% of the energy consumption and, simultaneously, the CO 2 emissions of modern buildings originate from air conditioning processes. These are traditionally based on electrically driven, mechanical compression chillers and heat pumps or classical burner systems, respectively. This demand is expected to rise in the future because of increased living standards and global climate change. 1 However, with alternative technologies, less exergetic (that is, closer to equilibrium) forms of energy, even low-temperature waste heat from industrial processes, can be employed for both heating and cooling. Solar heat as driving energy is especially interesting due to the high coincidence of cooling demand and solar irradiation. While multiple working principles for thermally driven heat-pumps can be realised, the evaporation-adsorption method has proven most feasible for this purpose and is briefly described in Fig. 1 and Table 1.The presented process renders cooling applications independent of precious electrical energy. If it is used for heating, the incorporation of environmental heat allows for considerable fuel savings. The coefficient of performance (i.e. the relation between useful and driving heat), power density, cost and operating lifetime of the complete machine are governed by the sorption material and its figures of merit, i.e. porosity, water sorption capacity, hydrophilicity and hydrothermal stability. 2,3 The achievable loading lift and also the required desorption temperature directly depend on the hydrophilicity of the material, i.e., the p/p 0 value at which adsorption occurs

JANIAK, C.; Eur. J. Inorg. Chem. 2012, 16, 2625-2634, http://dx.doi.org/10.1002/ejic.201101056 ; Fraunhofer-Inst. Solare Energiesyst., D-79110 Freiburg/Br., Germany; Eng.) -Lindner 34-244

The distinctive water sorption properties of microporous aluminium fumarate (s-shaped isotherm{,} narrow hysteresis{,} loading >0.3 g g-1 at a relative pressure as low as p/p0 = 0.3 under realistic working conditions) permit a large advancement of MOF-based sorption heat transformation processes{,} especially as we demonstrate that the favourable sorption properties are accompanied by an unprecedented cyclic hydrothermal stability. With regard to the application of heat transformation{,} where unhindered heat and mass transfer are crucial for fast ad-/desorption cycles and a high power density{,} the question of proper shaping was also addressed. A 300 [small mu ]m thick{,} polycrystalline{,} thermally well coupled and highly accessible coating of microporous aluminium fumarate was deposited on a metal substrate via the thermal gradient approach{,} and found to be stable for the first 4500 ad-/desorption cycles with water vapour