SGER- Exploratory Research on an Oxide Ion and Proton Co-Ionic Conducting

Tennessee Technological University, Cookeville TN

Investigators

Abstract

Abstract Proposal Title: SGER Exploratory Research on an Oxide Ion and Proton Co-Ionic Conducting Membrane for Fuel Cell Applications. Proposal Number: CTS-0620105 Principal Investigator: Chensheng Wang, Institution: Tennessee Technological University The technical challenges for proton exchange membrane fuel cells (PEMFCs) are thermal and water management, CO tolerance, cost, and durability. This proposal addresses these challenges by integrating studies of a new co-ion conducting composite membrane containing oxide ion conductive ceramic (Bi4V2(1-x)Ti2xO(11-3x), x=0.05-0.1, abbreviated as BITIVOX)) particles and/or fibers within a proton conductive solid acid CsH2PO4. This SGER proposal requests funding for materials and supplies plus supports one student part time while the materials are synthesized. The PI proposes to investigate the mechanism of co-ion conduction, and CO and direct methanol oxidation by oxide ions and oxygen reduction in such a surface implanted co-ion composite membrane will be assessed through systematic study of its compositions, structure and electrochemical performance. The uniqueness of the proposed research is to oxidize CO or methanol at the anode side of a fuel cell using an oxide ion, which is either transferred from the cathode side through the oxygen ionic conductive oxides in a proton conducting CsH2PO4 and/or directly exchanged from bleeding O2 into an oxide ion at the anode. Currently, there is a trend towards both decreasing solid oxide fuel cell operating temperature, while increasing that of the PEMFC. The co-ion fuel cells operating at 250oC are a new generation of fuel cells, which will combine the advantages of both SOFC and PEMFC. The unique idea of electrochemical oxidation of CO and methanol at the anode by oxide ion transferred from the cathode via oxide-ion-conducting ceramics and/or exchanged from bleeding O2 has opened a window for the development of a new generation of robust power systems. This Small Grant for Exploratory Research (SGER) seeks to prove that this novel composite membrane can be fabricated and that previous electrochemical results on the individual constituent fibers will in turn hold true for composite fiber mats. These BITIVOX mat-CsH2PO4 composite will be placed within a working fuel cell environment at temperatures up to 250C and subsequently tested for mechanical stability, electrochemical properties, and fuel cell performance. If successful, the PI anticipates that this SGER proposal will lead to a more detailed CAREER proposal where the composite fiber mat system would be modeled and characterized within a carefully crafted experimental and teaching plan.