Nano-structured Electrode Materials with Reduced Amount of Platinum Aimed for Hydro gen Evolution. Part I: Effect of cobalt

Abstract

The subject of this study is electrochemical and structural characterization of nano-dimenzioned composite electrode materials for hydrogen evolution consisted of Co, Pt or CoPt metallic phase and TiO2, both grafted on multiwalled carbon nanotubes (MWCNTs) as a support material. The main idea was to replace platinum entirely or to some extent as an electrode material. The electrode materials with different The common composition of the studied electrode materials was 10%Me + 18%TiO2 + MWCNTs, where Me = Pt, CoPt (1:1, wt.), CoPt (4:1, wt.) and Pt. The structural and surface changes, as well as their influence on electrocatalytic activity were analyzed by means of XRD, TEM, SEM and FTIR. It was found that Co considerably reduces Pt particle size, from 11 nm (in pure Pt metallic system) to 3–4 nm (in mixed CoPt systems). This is a reason for better activity of the electrode material with CoPt (1:1) metallic phase than that with pure Pt, while the CoPt (4:1) with very low quantity of Pt approaches the acitivity of the electrode material with pure Pt.