High-adaptability refrigeration under extreme temperatures in summer enabled by metal-organic framework

Extreme global climates in summer and frequent energy crises have led to an increasing demand for sustainable refrigeration; however, low-grade-thermal-energy-driven refrigeration at high ambient temperatures (≥ 40 °C) has rarely been studied. In this paper, we report a solar-driven efficient sorption refrigeration scheme for extreme ambient temperature in summer enabled by metal-organic framework-ammonia working pairs. MIL-101(Cr) consistently achieves an ammonia sorption capacity of 0.59 g·g^-1 contributed by the multiple sorption behavior of the host-guest interaction even when operating under condensation and sorption temperatures as high as 40 °C and 45 ^oC, respectively. Based on these findings, we construct a proof-of-concept device based on an MIL-101(Cr)-ammonia working pair. An impressive coefficient of performance of 0.387 is achieved when the device is subjected to high condensation temperatures (40 °C), low evaporation temperatures (10 °C), and desorption temperatures (100 °C). These results highlight the adaptability of this working pair to high temperatures. Our research indicates that this innovative approach holds promise as a future sustainable energy technology for various practical applications, including ammonia-based fuel systems, and for addressing both cold and thermal energy demands.