High-Throughput Synthesis of Zeolitic Imidazolate Frameworks and Application to CO2Capture

Abstract

A high-throughput protocol was developed for the synthesis of zeolitic imidazolate frameworks (ZIFs). Twenty-five different ZIF crystals were synthesized from only 9600 microreactions of either zinc(II)/cobalt(II) and imidazolate/imidazolate-type linkers. All of the ZIF structures have tetrahedral frameworks: 10 of which have two different links (heterolinks), 16 of which are previously unobserved compositions and structures, and 5 of which have topologies as yet unobserved in zeolites. Members of a selection of these ZIFs (termed ZIF-68, ZIF-69, and ZIF-70) have high thermal stability (up to 390°C) and chemical stability in refluxing organic and aqueous media. Their frameworks have high porosity (with surface areas up to 1970 square meters per gram), and they exhibit unusual selectivity for CO2 capture from CO2/CO mixtures and extraordinary capacity for storing CO2: 1 liter of ZIF-69 can hold ∼83 liters of CO2 at 273 kelvin under ambient pressure.