Carbon dioxide (CO2) separation will be required for climate change mitigation at an unprecedented scale in the future. Processes for CO2 separation include absorption, adsorption and the use of membranes. Membranes offer cost-effective and energy-efficient separation as well as continuous operation, as compared to the other processes. Efficient membrane processes require materials with high selectivity for, and high transmembrane flux of CO2, to keep membrane area, and therefore materials requirements low. Dual-phase, supported, molten-salt membranes are emerging as promising next-generation devices for CO2 separation as they remain functional at high temperatures where other common membrane materials lose selectivity and stability. In this class of membrane, Ag-supported, dual-phase, molten-carbonate membranes routinely demonstrate the highest CO2 fluxes. However, using Ag as a support incurs high cost. In this work, we demonstrate the self-assembly of a percolating, dendritic network of Ag within a low-cost Al2O3 supported, molten-carbonate membrane, achieving fluxes higher than membranes wholly supported by Ag. Ex-situ X-ray micro-computed tomography (µCT) was used to investigate Ag dendrite formation and demonstrated how the non-equilibrium conditions of membrane permeation can be used to add advantageous functionality to membranes in-situ. We report the highest flux of any metal-carbonate, dual-phase membrane to date (1.25 ml min-1 cm-2 at 650 °C), and ultrahigh permeabilities (10-11 mol m-1 s-1 Pa-1), outperforming the permeability requirement for economically competitive CO2 capture (10-13-10-12 mol m-1 s-1 Pa-1). Furthermore, these membranes achieved the permeance required for cost-effective CO2 capture from post combustion gas streams (10-7 mol m-2 s-1 Pa-1), whilst using one order of magnitude less silver on a membrane-volume normalised basis.

Dendritic silver self-assembly in molten-carbonate membranes for efficient carbon dioxide capture

Macromolecular Chemistry: The Second Century

[Author Benefits](https://scimeetings.acs.org/?utm_source=pubs_content_marketing&utm_medium=website&utm_campaign=0320_MCF_NPI_Launch_Spring_Homepage&ref=pubs_content_marketing)

[How to use SciMeetings](https://storage.googleapis.com/dl.morressier.com/acs/SciMeetings-ACSSpring2020-HowToGuide_M3020-Final.pdf)

[Frequently Asked Questions](https://storage.googleapis.com/dl.morressier.com/acs/SciMtng_ACSNMSp2020_FAQ_M3120_Final.pdf)

ACS Spring 2020 National Meeting & Expo

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.