AN ABSTRACT OF A THESIS

SUPERCAP ACITOR AND OXYGEN STORAGE MATERIALS FOR PROTON

EXCHANGE MEMBRANE FUEL CELL HYBRID SYSTEMS

Steven R. D'Souza

Master of Science in Chemical Engineering

Incorporation of hydrous ruthenium oxide into the electrocatalyst anode andcathode layers of a proton-exchange membrane fuel cell membrane was found to increasethe peak power and cell perfonnance at nonnal operating conditions. The goal of thisresearch focused on the development of amorphous hydrous ruthenium oxide(RUO28XH2O)as a supercapacitor material in proton exchange membrane fuel cells(PEMFC). RUO2.0.5H2Owas mixed with platinum electrocatalyst and sandwichedaround a Nafion@ membrane to fonn a single composite layer and an intrinsicPEMFC/supercapacitor system. The continuous and pulse power output of fuel cellswere measured by cyclic voltammetry (CV), nonnal pulse voltammetry and potentialsquare-wave voltammetry using H2/O2 as well as N2 feed gases. Preliminary resultsshowed that a RUO2.0.5H20 supercapacitor sub-layer doubled peak power output whileonly slightly decreasing the continuous power output. The slight decreases in continuepower output was due to the additional RUO2°0.5H20lowered the availability of activesurface area of platinum catalyst to hydrogen and oxygen, thus reducing the overallefficiency of the catalyst. Under potential square-wave voltammetry tests, RUO2.0.5H2Oexhibited seven times the amount of current per gram material as compared to platinumelectrocatalyst. This singular supercapacitor-electrocatalyst design perfonns the samefunctions of the more complex, costly, and heavier fuel celllsupercapacitor hybridsystems.

A secondary goal of this research seeks to study the influence of oxygen andhydrogen storage materials on PEM fuel cell perfonnance. An oxygen storage materialwith a chemical composition of CeO.86ZrO.l402was prepared and incorporated into thecathode electrode layer of a PEMFC. The presence of CeO.86ZrO.1402was also found toenhance the perfonnance of the fuel cell under pulsed conditions.

SUPERCAPACITOR AND OXYGEN STORAGE MATERIALS FOR PROTON

EXCHANGE MEMBRANE FUEL CELL HYBRID SYSTEMS

A Thesis

Presented to

The Faculty of the Graduate School

Tennessee Technological University

By

Steven Raymond D'Souza

In Partial Fulfillment

Of the Requirements for the Degree

MASTER OF SCIENCE

Chemical Engineering

May 2005

CERTIFICATE OF APPROVAL OF THESIS

SUPERCAPACITOR AND OXYGEN STORAGE MATERIALS FOR PROTON

EXCHANGE MEMBRANE FUEL CELL HYBRID SYSTEMS

By

Steven Raymond D'Souza

Graduate Advisory Committee:

~ ~~h~on 4,- }8- (JS-Date

1-~8 -oS-Date

~Dr. Jiahong Zhu

Lr2!~5-Date

Approved for the Faculty:

~~Associate Vice President for Research andGraduate Studies

Datf 1)..1 bS"

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