Magnetoelectrocatalysis of the Oxygen Reduction Reaction (ORR)

Fundamental kinetic studies of the catalytic effect of localized magnetic fields on the oxygen reduction reaction (ORR) are conducted at platinum electrodes in the organic solvent acetonitrile with tetrabutylammonium tetrafluoroborate (TBABF₄) electrolyte. Electrodes are modified with magnetic particles suspended in a Nafion film. The magnetic particles are SiMag C1 (ChemiCell Gmbh) superparamagnetic maghemite particles coated with methyl silane to make them chemically inert. Cyclic voltammetric results for a Nafion film in oxygen free and oxygen saturated conditions are shown. For the composite of magnetic particles in Nafion, data for saturated oxygen are shown. Enhanced heterogeneous electron transfer kinetics are observed. Currents increase by 20% and the peak splitting is reduced by 400 mV (from 1.8 V to 1.4 V). The overpotential as measured at current half height is decreased by 200 mV. Particles with different magnetic field strengths are examined as well as demagnetized particles.