EAGER: Exploring a New Bi-ionic Transport Mechanism in Dual-Phase Electrochemical CO2 Separation Membranes

University Of South Carolina At Columbia, Columbia SC

Investigators

Abstract

1340269 - Huang The exploratory research proposed is aimed at understanding from a fundamental science perspective why and how dual-phase mixed oxide-ion and carbonate-ion conducting membranes containing highly interconnected ionic channels exhibit superior CO2 transport characteristics. Intellectual Merits The key intellectual merit of the proposed research is centered on the unique parallel bi-ionic pathways model that extends the ionic transfer zones from triple-phase boundaries (3PBs) to double-phase boundaries (2PBs) and is complemented by the experiments of 1) identification of a new intermediate surface species with in-situ Raman spectroscopy and 2) verification of the bi-ionic transport model through an MC-flooded permeation cell. Specifically: o For the first time C2O5 2- polycarbonate ions are proposed as an intermediate surface species that are reduced by O2- at 2PBs of MC/oxide-ion conductor interface o Confirmation of the formation of CO3 2?(CO2)n containing strong CO bonds and structurally stable chainlike [CnO2n+1] moieties by successively binding the simple nucleophilic anion CO3 2? with several CO2s through in-situ Raman spectroscopy o Verification of the proposed bi-ionic transport model through MC-flooded surface blocking permeation cell Broader Impacts Discovering energy-efficient and cost-effective CO2 separation membranes is of prime importance to the development and deployment of CO2 capture technologies in existing fossil fueled power plants. This research has the potential to transform conventional wisdom in understanding ionic transport behaviors in heterogeneous systems, and ultimately lead to rationally designed high-performance ionic systems for a variety of energy applications. One example is the design of (CO2)n chainlike compounds such as solid polycarbonates CnO2n+1R2 (R=large-size group) for highly efficient large-scale CO2 scrubbing. Another example is the design of CnO2n+1H2, a class of potential candidates for high-energy density materials as they decompose exothermically into nCO2 + H2O products, but are locally stable because of the existence of substantial dissociation barriers. Both graduate and undergraduate students including minority and underrepresented groups will play an active role in this research through clearly identified, focused research projects. The importance and potential impact of ongoing scientific advances in the area of CO2 capture and storage technologies will be disseminated to the general public via the annual "Edison Lecture Series" program of the College of Engineering and Computing at the University of South Carolina.