Structural and electrocatalytic properties of Pt/C and Pt-Ni/C catalysts prepared by electrochemical dispersion

Abstract

The structural and electrocatalytic properties of Pt/C and Pt-Ni/C catalysts prepared by the electrochemical dispersion of metals under the action of pulse alternating current in a solution of NaOH were studied. Using X-ray diffraction analysis and scanning and transmission electron microscopy, it was found that the synthesized Pt/C catalysts contained active constituent particles with the average size D 111 = 10.6 nm with a predominantly cubic shape. Upon the dispersion of a Pt3Ni alloy, the Pt-Ni/C catalyst containing the particles of a stoichiometric metal phase of Pt3Ni (D 111 = 9.6 nm) and also Pt x Ni particles (x > 3) enriched in platinum (D 111 = 8.1 nm). The synthesized catalysts possessed high electrocatalytic activity and stability in the reaction of methanol oxidation. The characteristics of these catalysts as anodes in the membrane-electronic unit of a hydrogen-air solid-polymer fuel cell were studied.