Aluminum formate, Al(HCOO)<sub>3</sub>: An earth-abundant, scalable, and highly selective material for CO<sub>2</sub> capture.

Evans, Hayden A; Mullangi, Dinesh; Deng, Zeyu; Wang, Yuxiang; Peh, Shing Bo; Wei, Fengxia; Wang, John; Brown, Craig M et al. · Sci Adv · 2022

basic_science · Level V

Where this comes from

Abstract

A combination of gas adsorption and gas breakthrough measurements show that the metal-organic framework, Al(HCOO)<sub>3</sub> (ALF), which can be made inexpensively from commodity chemicals, exhibits excellent CO<sub>2</sub> adsorption capacities and outstanding CO<sub>2</sub>/N<sub>2</sub> selectivity that enable it to remove CO<sub>2</sub> from dried CO<sub>2</sub>-containing gas streams at elevated temperatures (323 kelvin). Notably, ALF is scalable, readily pelletized, stable to SO<sub>2</sub> and NO, and simple to regenerate. Density functional theory calculations and in situ neutron diffraction studies reveal that the preferential adsorption of CO<sub>2</sub> is a size-selective separation that depends on the subtle difference between the kinetic diameters of CO<sub>2</sub> and N<sub>2</sub>. The findings are supported by additional measurements, including Fourier transform infrared spectroscopy, thermogravimetric analysis, and variable temperature powder and single-crystal x-ray diffraction.