This Small Business Innovation Research (SBIR) Phase II project is in the general area of analytical and surface chemistry and in the subfields of electrochemistry and materials chemistry. The goal of this activity is the development of highly dispersed, small particle, supported goal electrocatalysts for the reduction of dioxygen in alkaline media. In the preceding Phase I research which was supported under NSF grant ISI-8660688, Physical Sciences, Inc. demonstrated that the direct electroreduction of dioxygen to water was enhanced on the 100 surface of goal. The company further demonstrated that small-particle gold catalysts could be fabricated on carbon supports, and that the use of these electrocatalysts gave rise to diminished formation of the undesired hydrogen peroxide electroreduction product. In the present Phase II activity, the previous Phase I work is being extended and broadened in scope. Research tasks for the current effort include (1) preparation of highly dispersed supported gold electrocatalysts and development of corrosion resistant support materials for use in alkaline media; (2) tailoring of the gold crystallite structure through variation of both particle size and fabrication conditions to produce (100) preferentially oriented gold particles; (3) determination of the crystallite structure of the gold particles using extended x-ray absorption fine structure (EXAFS) spectroscopy both in vacuo and in situ in an actual operating fuel cell; and (4) measurement of electrode performance in a half-cell configuration under realistic operating conditions. The new electrocatalysts derived from this research could have broad, technologically important applications.
