Jingjing Tong

Remarkable O2 permeation through a mixed conducting carbon capture membrane functionalized by atomic layer deposition

The development of energy-efficient and cost-competitive carbon capture technology is of vital importance to effective reduction of carbon emissions and mitigation of global climate change. The present work reports that a highly energy-efficient electrochemical carbon capture membrane consisting of a carbonate and silver phase exhibits a remarkably high rate of O2 permeation after the silver phase is functionalized with a nanoscale layer of Al2O3 by atomic layer deposition. The resulting permeation flux ratio of O2 to CO2 was 1.5:1, a complete reversal from 1:2 of the conventional membrane. The mechanisms of this exceptionally high rate of O2 permeation were investigated by in situ Raman spectroscopy and theoretical DFT calculations. The results revealed that LiCO4− as the active surface species was responsible for the enhanced O2 permeation. A new CO2/O2 transport model based on a “cogwheel” migration mechanism of CO42− was presented to explain the experimental results with excellent agreement.

A self-forming dual-phase membrane for high-temperature electrochemical CO2 capture

We report here a dual-phase mixed CO32−- and e−-conducting CO2 capture membrane self-formed at high temperatures from NiO and molten carbonate. The levels of flux density and selectivity demonstrated by this membrane were better than those of the conventional “size-sieving” inorganic and “dissolution–diffusion” organic counterparts. These features of the membrane we made, combined with its resistance to sintering, low cost, and ease of fabrication, make its use a promising CO2 capture technology.