Synthesis and characterization of ions-exchanged zeolite Y for adsorption heat transformation

Among the available and performant materials, zeo-types ones are considered promising for adsorption heat transformation processes. Indeed, due to their partial hydrophilic behaviour, low regeneration temperatures and a relatively high-water adsorption capacity, they actually fit the desired features for this kind of application. This work presents the synthesis and characterization of modified Y type zeolites designed to improve water adsorption behavior for adsorption heat transformation systems. A high silica zeolite Y was produced and further modified through rare earth ion exchange, ammonium exchange, and steaming to reduce hydrophilicity and shift the adsorption isotherm toward higher relative pressures. Structural analyses confirmed framework changes and partial dealumination caused by these treatments. Water sorption measurements showed that the combined NH4+ and La3+ exchange offered the best balance between adsorption capacity and hydrophobicity, approaching the performance of the benchmark DDZ 70 material. Stability tests demonstrated good cyclability, and the heat of adsorption remained within the expected range for Y type zeolites. Overall, the modified materials show promising potential for low temperature thermal energy storage and adsorption heat pump applications.