Controlled size formation of electrodeposited Pt–Ru nanostructured catalysts using chelating compounds

The electrodeposition of Pt and Ru on a oxidized graphite cloth from H2PtCl6 and RuCl3 solution containing trisodium citrate (Cit), disodium tartrate (Tar) and disodium dihydrogen ethylenediaminetetraacetate (Na2H2EDTA) as complexants was investigated. SEM image of the electrode prepared without complexant showed a continuous compact and rough deposit that covers the entire graphite fibers surface displaying the structure of a coating film, whereas particles with uniform size and globular shape regularly distributed over the support were obtained when the complexants were added to the solution. Thus, EDX and XRD analysis revealed changes in Pt–Ru catalyst composition. It was concluded from electrocatalytic activity measurements that the electrodes prepared using chelating compounds exhibited better CO tolerance and performance for methanol oxidation than that without complexant.

► Electrodeposited Pt–Ru catalysts prepared from solutions containing complexants.
► Complexants contributed to control the structural characteristics of the deposits.
► Better deposit dispersion, and reduction in particle size were observed.
► Pt–Ru catalyst prepared using EDTA exhibits better performance for CH3OH oxidation.