Glycerol and formic acid electro-oxidation over Pt on S-doped carbon nanotubes: Effect of carbon support and synthesis method on the metal-support interaction

Abstract

The effects of catalyst support and synthesis process on the interaction between Pt nanoparticles (NPs) and S-doped carbon nanotubes (SCNTs), and the resultant electro-oxidation catalytic performance of glycerol, formic acid and CO were systematically researched. Pt NPs on SCNTs had better electro-oxidation catalytic performances than that of Pt NPs on CNTs. The doped S in thiophene-like structure (C-S-C) activated the neighboring C atoms to interact with Pt NPs, improving the catalytic performance with stronger ability to remove poisonous intermediates. The formed C-S-C had a synergistic effect with the neighboring Pt-C, promoting the adsorption and activation of reactants. The improved metal-support interaction resulted in Pt with smaller nanoparticle size and more exposed active sites. In different synthesis process, Pt NPs were more likely to interact with activated C neighboring S in ethylene glycol reduction method. However, defects containing doped S preferred to interact with Pt NPs in impregnation method. The research results indicated that rationally regulating the surface properties of carbon support and choosing an appropriate catalyst synthesis strategy to intensify the required metal-support interaction can greatly improve the catalytic performance.