Influence of complexing agents on the preparation of bimetallic platinum–ruthenium catalysts supported on O-functionalized graphite cloths

Abstract Electrodeposition of bimetallic Pt–Ru catalysts on O-functionalized graphite cloths from H 2 PtCl 6 and RuCl 3 solutions containing trisodium citrate (Cit) and disodium dihydrogen ethylenediaminetetraacetate (Na 2 H 2 EDTA) was investigated. SEM analysis of the electrode prepared without complexant showed a relatively compact and rough deposit displaying a ‘tree cortex’ structure, whereas uniform size and globular shape particles regularly distributed over the support surface were obtained using citrate and Na 2 H 2 EDTA as complexants. In addition, XRD diffraction and EDX analysis revealed that the catalysts prepared using the complexants showed smaller size particles and lower Ru content. Electrocatalytic activity measurements indicated that the most active electrode for methanol oxidation was obtained with Na 2 H 2 EDTA as additive.