No abstract

Nitric acid modified Mesoporous carbon (CMK-3) supported Pt particles have been prepared by chemical reduction with NaBH4 as a reducing agent. Energy dispersive spectrometer shows that the catalysts have some oxygenic functional groups. The activity of the composite catalysts for methanol electro-oxidation was investigated by using cyclic votammogram and chronoamperometry in acid media. The results indicated that modified mesoporous carbon can improve the catalytic ability of Pt catalyst for methanol electro-oxidation and antipoison capability for CO. The composite electrode modified by 0.23 g nitric acid has the highest electrochemical ability.

Well-dispersed and low Pt content Pt–Ru/C nanoparticles were prepared by a developed impregnating reduction method with sodium citrate as stabilizer. The as-prepared Pt–Ru/C catalysts were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), and energy dispersive X-ray (EDX) analysis. TEM showed that the Pt–Ru particles were quite uniformly distributed on the surface of the carbon with an average particle size of 3.5–4.5 nm. The effect of pH values on methanol electro-oxidation reaction was examined by cyclic voltammetry (CV) and chronoamperometry (CA). Pre-adsorbed CO monolayer stripping was used to evaluate the antipoisoning ability. The results showed that Pt–Ru/C (pH = 8) catalyst had the highest catalytic activity and stability toward the oxidation of methanol. Finally, comparing Pt–Ru/C (Pt–Ru 20 wt.%, Pt/Ru = 1:1) catalysts with Pt/C (Pt 20 wt.%), the onset potential was 200 mV lower and electrochemical active area was much bigger.