Observation of magnetic effects in oxygen reduction electrocatalysis

Fuel cell polarization curves of a novel platinum alloy (Pt3Co/C) catalyst displayed a unique mass transport signature unidentifiable with general fuel cell operation. Physico-chemical characterization utilizing various methods was carried out to probe the properties of the catalysts and to compare with standard commercially available catalysts from ETEK. Magnetic measurements were also used to determine the properties and type of magnetic character the catalysts hold.;The intrinsic magnetic characteristics of the electrocatalyst in the fuel cell become apparent at relatively low operating pressures of oxygen; this is mainly due to the magnetic forces affected by concentration gradients. Other electrochemical experiments reveal the nature of the catalyst as one having high concentration of cobalt on the surface in the form of islands, which was probed with alkaline based cyclic voltammetry. SEM imagery confirms the particle sizes determined by XRD Scherrer particle size estimation. There is indication from the elemental analysis and XRD that the commercially available Pt3Co/C electrocatalysts available from ETEK alloys are not truly the 3:1 Pt:Co atomic ratio they claim to be due to minor sublimation of cobalt and subsequent formation of cobalt clusters in the carbon support at high temperatures.;Future research is suggested in the form of new synthetic techniques and trials to achieve a more hard magnetic material which will further enhance the mass transport properties of the electrocatalyst. Other electrochemical experiments are suggested to determine the magnetic effects of other charged species relative to the oxygen reduction reaction (ORR).