Publication Date:
2015-12-19
Description:
Metal organic frameworks (MOFs) built from a single small ligand typically have high stability, are rigid, and have syntheses that are often simple and easily scalable. However, they are normally ultra-microporous and do not have large surface areas amenable to gas separation applications. We report an ultra-microporous (3.5 and 4.8 Å pores) Ni-(4-pyridylcarboxylate) 2 with a cubic framework that exhibits exceptionally high CO 2 /H 2 selectivities (285 for 20:80 and 230 for 40:60 mixtures at 10 bar, 40°C) and working capacities (3.95 mmol/g), making it suitable for hydrogen purification under typical precombustion CO 2 capture conditions (1- to 10-bar pressure swing). It exhibits facile CO 2 adsorption-desorption cycling and has CO 2 self-diffusivities of ~3 x 10 –9 m 2 /s, which is two orders higher than that of zeolite 13X and comparable to other top-performing MOFs for this application. Simulations reveal a high density of binding sites that allow for favorable CO 2 -CO 2 interactions and large cooperative binding energies. Ultra-micropores generated by a small ligand ensures hydrolytic, hydrostatic stabilities, shelf life, and stability toward humid gas streams.
Electronic ISSN:
2375-2548
Topics:
Natural Sciences in General
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