Two kinds of carbon-support 20% Pd/C catalysts for use in direct ethanol fuel cell (DEFC) have been prepared by an impregnation reduction method using NaBH4and NaH2PO2as reductants, respectively, in this study. The catalysts were characterized by XRD and TEM. The results show that the catalysts had been completely reduced, and the catalysts are spherical and homogeneously dispersed on carbon. The electrocatalytic activity of the catalysts was investigated by electrochemical measurements. The results indicate that the catalysts had an average particle size of 3.3 nm and showed the better catalytic performance, when NaBH4was used as the reducing agent. The electrochemical active surface area of Pd/C (NaBH4) was 56.4 m2·g−1. The electrochemical activity of the Pd/C (NaBH4) was much higher than that of Pd/C (NaH2PO2).

Direct ethanol fuel cells are considered a promising power source for future portable electronic and automotive applications. This article reviewed the synthetic methods commonly used to prepare Pd-based catalysts for the ethanol electrooxidation in alkaline media. The progress in the mechanism studies of ethanol oxidation reaction (EOR) on Pd electrode in alkaline medium by cyclic voltammetry and electrochemical in situ FTIR spectroscopy was also reviewed. The recent studies revealed that the EOR is fairly complicated, and it is difficult in CC bond cleavage for the complete oxidation of ethanol to CO2, and ethanol is selectively oxidized to acetate on Pd-based catalysts in alkaline media. Overall, what is most important is to explore new Pd-based alloy catalysts with high ability to break the CC bond to promote complete oxidation of ethanol as well as increase the efficiency of DEFCs.

The Ru/C nanocomposites with loading of 20wt% were prepared by ethylene glycol in the presence of XC-72. Carbon-supported Ru nanoparticles were decorated with Pt by spontaneous deposition method after Ru surface oxides were reduced in the hydrogen atmosphere at 180 for 2h. TEM indicated that the average particle size of catalyst was about 4nm with excellent dispersion and the XRD analyzing results showed that Pt had decorated on surface of Ru. The anti-poisoning ability was studied by pre-adsorbing CO striping voltammetric curves in 0.1M HClO4. Catalytic activities of the prepared Pt/Ru/C were studied by cyclic voltammetry in a solution of 0.5 mol/L CH3OH + 0.1 mol/L HClO4. The results showed that the oxidation current density was far more than 60wt% RuPt/C (E-TEK) and 20wt% Pt/C (Johnson Matthey). At the same time, the study also showed that the prepared catalyst not only had a higher catalytic activity to methanol, but also had lower Pt loading.

A new approach of spontaneous deposition was carried out to prepare the Ru/Pt film electrocatalyst for direct methanol fuel cells. This deposition method just made Pt like a ‘skin’ covered Ru films, which reduced the load of Pt but obtained a higher activity. The Pt-modified Ru films electrode was studied with the cyclic voltammetries and in-situ ATR-SEITA spectra on methanol oxidation. Compare to bare Ru and Pt, the bands of the adsorbed CO and water observed in IR spectra can be assigned. The present results give a clue for designing new electrocatalysts for DMFCs.

Fuel cell is one of the most promising power sources towards high-efficiency, low-emission and environmental benign application. In pursuit of a higher performance, electrocatalyst is a crucial research focus. Compared with commercial carbon support, TiO2exhibits the advantages of higher stability, higher porosity and stronger metal-support interaction. In this article, we give a brief overlook on the influence of diverse crystal and morphology structures on their eletrocatalytic property in fuel cells. Besides, to better meet the demand of practical electrocatalysts, three different methods are summarized to overcome its relatively poor electrical conductivity. Overall, TiO2is a promising support material of electrocatalysts in fuel cells.