A Durable Sorbent to Unlock the Sustainable Future: Room Temperature and Scalable Production of Aluminium Formate through Mechanochemical Method for Efficient and Selective CO2 Capture.

Abstract

Carbon dioxide (CO₂) capture is essential for addressing climate change, requiring the development of efficient, scalable, and sustainable sorbent materials. This study presents microporous aluminum formate (ALF) synthesized via a novel, room-temperature mechanochemical ball milling method. This green, solvent-free approach enables kilogram-scale production using inexpensive raw materials under ambient conditions. The resulting ALF exhibits a high CO₂ adsorption capacity of 3.97 mmol·g^-1 at 1 bar and 278 K, with a moderate isosteric heat of adsorption (Q_st = 42.1 kJ·mol^-1), allowing energy-efficient regeneration. ALF also demonstrates rapid adsorption kinetics (90% uptake within 5 min), excellent recyclability over 100 cycles, and remarkable CO₂/N₂ selectivity of 341, highlighting its suitability for practical applications. Importantly, the material maintains significant CO₂ uptake (3.26 mmol·g^-1) even under humid conditions. ALF can be shaped into mechanically robust, millimeter-sized pellets, making it ideal for industrial-scale deployment. The comparative evaluation shows that ALF's CO₂ capture performance rivals leading MOFs such as CALF-20, UTSA-16, MOF-74 variants, and SIFSIX-series materials. Overall, ALF emerges as a cost-effective, durable, and high-performing sorbent, offering a promising pathway toward scalable, sustainable carbon capture solutions.