Enzyme-embedded metal-organic framework membranes on polymeric substrates for efficient CO2capture

Abstract

© 2017 The Royal Society of Chemistry. In this work, carbonic anhydrase (CA) molecules were embedded into metal-organic frameworks (MOFs) via physical absorption and chemical bonds, which could overcome the enzymatic inactivation and the poor separation property of pristine MOF materials. And then, these nanocomposites (enzyme-embedded MOFs) as the crystal seeds were in situ grown on oriented halloysite nanotube layers to develop novel biocatalytic composite membranes. These membranes exhibited optimal separation performance with a CO2/N2selectivity of 165.5, about 20.9 fold higher than that of the membrane without embedded CA molecules, surpassing the Robeson upper bound (2008). At the same time, the CO2permeance increased about 3.2 fold (from 7.6 GPU to 24.16 GPU). Importantly, the biocatalytic composite membranes showed good stability and mechanical properties and were easily scalable, which could be extended to industrial applications.