Highly catalytic activity of Pt electrocatalyst supported on sulphated SnO2/multi-walled carbon nanotube composites for methanol electro-oxidation

Highly catalytic active platinum nanoparticles supported on sulphated SnO2/multi-walled carbon nanotube composites (Pt–S–SnO2/MWCNT) are reported. As a novel catalyst support, S–SnO2/MWCNT composites with both electron and proton conductivity can improve the catalytic activity and utilization of Pt catalyst in direct methanol fuel cell. X-ray diffraction and transmission electron microscopy show that the sulphated SnO2 and Pt nanoparticle is coexist in the Pt–S–SnO2/MWCNT composites and coated uniformly on the surface of the MWCNTs. Fourier transform infrared spectroscopy analysis proves that the MWCNT surfaces are modified with sulphated SnO2 and a high concentration of SOx, and adsorbed OH species exist on the surface of the sulphated SnO2. Electrochemical studies are carried out using cyclic voltammetry, chronoamperometry and CO stripping voltammetry. The results indicate that Pt–S–SnO2/MWCNT catalysts have much higher catalytic activity and CO tolerance for methanol electrooxidation than Pt-SnO2/MWCNTs, commercial Pt/C and PtRu/C.

► Pt–S–SnO2 composites supported on MWCNTs as new catalysts were synthesized.
► Pt–S–SnO2/MWCNT catalyst show higher catalytic activity for methanol electro-oxidation.
► The higher catalytic activity is due to the sufficient electrical and proton conductivity of Pt–S–SnO2/MWCNT composites.