The effect of diluting ruthenium by iron in RuxSey catalyst for oxygen reduction

This study has focused on the synthesis of novel oxygen reduction reaction (ORR) chalcogenide catalysts, with Ru partially replaced by Fe in a cluster-type RuxSey. The catalysts were obtained by thermal decomposition of Ru3(CO)12 and Fe(CO)5 in the presence of Se. As indicated by the XPS data, the composition of catalyst nanoparticles depends on the solvent used (either p-xylene or dichlorobenzene). The presence of iron in synthesized catalysts has been confirmed by both EDAX and XPS. Voltammetric activation of the catalysts results in a partial removal of iron and unreacted selenium from the surface. The ORR performance of electrochemically pre-treated catalysts was evaluated using rotating disk and ring-disk electrodes in a sulfuric acid solution. No major change in the ORR mechanism relative to the Se/Ru catalyst has been observed with Fe-containing catalysts.