Economical solid polymer electrolyte fuel cells (SPEFCs) have potential commercial applications for example as auxiliary power fuel cell systems for cruise ships, offshore platforms, and remote navigation systems. Compared to other currently used electricity generating systems, fuel cells offer many advantages, including (1) high fuel to electricity conversion efficiency at both rated and part load; (2) molecular construction; and (3) low pollutant levels. A major impediment to the commercialization of SPEFC is the high cost of the unsupported platinum electrocalyst. In this work PIs plan to develop high utilization pulse plated carbon supported electrocatalysts for SPEFC applications which reduce the platinum cost substantially relative to the state-of-art. Using their Small Business Innovation Research (SBIR) Phase I grant, the PIs demonstrated a ten-fold decrease in platinum cost. Their high utilization electrocatalyst concept is based on Nafion impregnation of a carbon gas diffusion electrode followed by pulse current catalyzation (PCC) with platinum. They electrodeposit small platinum catalyst particles (30 angstrom) only in regions with electronic and ionic accessibility. The platinum utilization in this electrocatalyst is therefore high. Because a major impediment to the commercialization of SPEFCs is the high cost of the platinum electrocatalyst, this technique could be an enabling technology for commercially viable electrocatalysts for SPEFC. Another potential application for their Nafion impregrated electrocatalyst is for poisoning resistant oxygen sensing electrodes. Currently the electrocatalyst used as a cathode for oxygen sensing is poisoned by a soluble lead species from the anode. Since Nafion is a proton selective membrane, this electrode will retard the transport and poisoning of the oxygen sensing cathode by lead. This is an SBIR Phase II grant.
