Investigation of the nanometals (Ni and Sn) in platinum binary and ternary electrocatalysts for methanol electrooxidation

The main purpose of our research is focused to increase anodic catalysts activity and thus to decrease noble metal loading in anodes for electrooxidation of methanol. Binary and ternary catalysts dispersed in chitosan, Pt–Ni, Pt–Sn and Pt–Ni–Sn are synthesized by reduction of appropriate metal salts with NaBH4 in the chitosan solution. UV–vis spectra and transmission electron microscopy (TEM) images of the catalysts reveal the presence of metal nanoparticles (NPs). Performance of Pt–Ni, Pt–Sn, and Pt–Ni–Sn nanocomposites for methanol electrooxidation are examined by cyclic voltammetery and chronoamperometry methods. The effect of some experimental factors such as methanol, chitosan and electrolyte (H2SO4) concentrations, Ni and Sn amounts dispersed in chitosan on the current density and potential for the oxidation of methanol are studied and optimized. The electrochemical measurements show that the activity of Pt–Ni–SnNPs catalyst for methanol electrooxidation is higher than the activity of PtNPs, Pt–NiNPs and Pt–SnNPs catalysts.

► Binary and ternary catalysts dispersed in chitosan, Pt–Ni, Pt–Sn and Pt–Ni–Sn are synthesized. ► The GC/Pt–SnNPs, GC/Pt–NiNPs and GC/Pt–Ni–SnNPs electrodes as active electrocatalysts for oxidation of methanol. ► Improvement the electrode performance for methanol electrooxidation by addition of Sn and Ni nanoparticles into Pt catalyst. ► More porous matrix of chitosan improves the electrode performance.