The cathode side oxygen reduction reaction (ORR) in a typical PEM fuel cell is the slow catalytic step. Understanding the ORR and its behavior on a Pt surface has implications for the design of fuel cell catalysts, in the choice of Pt alloys for optimizing the ORR. Measurement of ORR kinetic parameters in situ in a fuel cell via pulse voltammetry is a means of evaluating catalyst performance under clean, surface refreshed conditions due to the potential program of a normal pulse voltammetry experiment. A Tafel slope of 98mV/decade was determined for the ORR on Pt/C fuel cell electrodes in situ, which compares well with the literature.
A microplasma-based method for the synthesis of nanocatalysts with finely controlled composition and structure of particular interest to fuel cell electrocatalysis is developed, and found to produce high purity Pt nanoparticles. Pt nanoparticles containing Co and Fe are also synthesized, with fine size control and narrow size distributions.
High temperature (120C) fuel cell operation is a targeted in the near future for benefits in fuel choice tolerance, and sizing of balance of plant components by eliminating external humidification. The durability of a resin bonded bipolar composite plates is evaluated, and 1100hours of runtime under 120C and low relative humidity conditions are demonstrated.