Chemical Sciences and Engineering Division

 Technical Seminar

Wednesday, November 14, 2007

3:00 p.m.

Y-Wing Auditorium

Building 205

High-Temperature Steam Electrolysis for Hydrogen Production

Presented by:  Jennifer Mawdsley

Abstract

                High-temperature steam electrolysis (HTSE) using heat from a nuclear reactor is one route being investigated as a means to make affordable hydrogen in the longer term.  This process splits water with a combination of heat and electrical energy using the technology of solid oxide fuel cells.  The process depends on multiple ceramic cells arranged in “stacks” identical to solid oxide fuel cell designs, but operating with a reverse current flow.  The stack provides for a manageable voltage/current input as well as a manufacturable cell size.  However, increased cell area and an increase in the number of components in the stack assembly introduce new sources of defects that can lead to performance degradation.

We have been investigating the causes of HTSE stack degradation by examining cells from stacks that had been operated for 1000 and 2000 hours.  Our approach to identifying the causes of degradation was to map the surfaces of cells using four-point resistivity measurements and X-ray fluorescence, followed by Raman spectroscopy and sectioning of the cells to analyze the cross-sections of specific regions using SEM.  In addition, we are working to develop alternative electrode materials for high temperature steam electrolysis.