Transforming Low-Grade Heat into Sustainable Cooling and Heating with Multicomponent Adsorbents

Rapid growth in fossil-fuel consumption has amplified the severity of global climate issues, making the deployment of renewable energy solutions increasingly imperative. Among candidate approaches, adsorption-based technologies are attractive; however, the limited adsorption capacity and kinetic performance of traditional adsorbents constrain composite-cycle efficiency and hinder large-scale implementation. In this work, we develop and evaluate a new class of composite adsorbents prepared by impregnating metal–organic frameworks (MOFs) with hygroscopic chloride salt solutions (LiCl, CaCl2, and MgCl2). Owing to their enhanced sorption characteristics, the resulting materials support an integrated adsorption cycle in which one device can simultaneously realize refrigeration, space heating, seawater desalination, and power generation. Under standard operating conditions, experiments demonstrate that MOF–vermiculite composites deliver a cooling coefficient of performance (COP) of 0.71, a heating COP (COPh) of 1.30, a specific power-generation output of 27.2 kJ/kg, and a desalination yield of 0.71 g/g. Collectively, these metrics outperform the majority of previously published results, indicating that composite adsorbents can substantially improve the efficiency and practicality of renewable energy conversion systems.