Abstract
The development of CO2 capture technology is essential as a global warming mitigation technology that will lead to the suppression of climate change. Gas separation membranes have great potential for direct air capture (DAC), which captures CO2 directly from the atmosphere, as well as from large CO2 emission sources, due to their low energy consumption and small footprint. However, membrane–based DAC has never been considered because of its low CO2 permeance. Recently, there have been report of high CO2 permeance membranes which would be promising candidate for DAC process. In this review paper, the recent studies of membranes with high CO2 permeance are summarized and discuss with molecular design of membranes in addition to our recent efforts to improve CO2 selectivity of nanometer–thick freestanding membranes by chemical modification of the membrane surface.
