Qun Jie Xu

Preparation and Electrocatalytic Characteristics Research of Pd/C Catalyst for Direct Ethanol Fuel Cell

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 NaBH4 and NaH2PO2 as 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 NaBH4 was 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).

Effect of Super-Hydrophobic Surface on the Corrosion Performance of Copper and Copper Alloys

With copper and copper alloys widely used, copper corrosion has already caused huge economic losses. Super-hydrophobic surface treatment, a new kind of corrosion resistant technology, can effectively inhibit metal corrosion. This paper introduces the basic issues and the construction methods of copper and copper alloys super-hydrophobic surface. The effect of super-hydrophobic surface on the corrosion performance of copper and copper alloys is analyzed emphatically. Recent developments of super-hydrophobic surface and the existed technical barriers are also summarized in the paper.

A Review of Pt-Based Anode Catalysts Preparation for Direct Ethanol Fuel Cell

Due to the intensifying energy crisis, the fuel cell research gradually becomes a hot spot, because it is non-toxic, cleaning, inexpensive and easy to obtain. However, there are still many problems in DEFC research, such as cathode, anode catalyst, battery electrode preparation and others. This paper reviews the preparation methods of DEFC anode catalyst, including impregnation reduction method, microemulsion method, and the other methods.

A Review of Pd-Based Electrocatalyst for the Ethanol Oxidation Reaction in Alkaline Medium

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.

Anatase TiO2 Films via a Sol-Gel and Hydrothermal Crystallization for Enhanced Corrosion Resistance

Anatase of TiO2films were supplied on the surface of 316L stainless steel by a sol–gel process followed by hydrothermal treatment in water. The as-prepared samples were characterized with filed emission scanning electron microscope (FESEM), transmission electron microscopy (TEM), atomic force microscopy (AFM) and Raman spectroscopy. The corrosion performances of the films in 3.5 wt% NaCl solution were evaluated by electrochemical impedance spectroscopy (EIS) and polarization measurements. The results revealed that the corrosion resistance of the TiO2 films via the hydrothermal treatment at 170°C for 4h exceeded that of the counterparts treated by conventional calcination at 450°C. This could be attributed that the surface of such a sample was more compact and uniform, relatively well-crystallized, able to act as an optimal barrier layer to metallic substrates.

Fabrication of Hydrophobic Surfaces and its Electrochemical Research on Copronickel B30

A novel hydrophobic film was prepared by Stearic acid (SA) chemically adsorbed onto the cupronickel B30 surface. The film properties were characterized by means of water contact angle measurement and electrochemical techniques. The results indicate that the structure of the adsorbed film is hydrophobic, and the contact angle is 113.82° for water. AC impedance and polarization curve measurements show that the corrosion resistance of cupronickel B30 modified by stearic acid is improved remarkably, and the inhibition efficiency reached 66.85%. After hydrophobic modified by stearic acid, the inhibition efficiency could reach 88.85% in 3% NaCl solution with the concentration of 0.1 g/L Na2WO4.

Preparation of Low Pt-Decorated Ru/C Catalyst and Electrochemical Research

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.

Poly (Divinylbenzene) Particles of Large Specific Surface Area Prepared by Dispersion Polymerization

Porous polydivinylbenzene particles were prepared by dispersion polymerization, using AIBN as initiator, acetonitrile as solvent, calcium carbonate and polypyrrolidone used as dispersion stabilizer and porogen. Ratio of dispersion stabilizer with monomer affects the specific surface area and porous structure. Calcium carbonate and polypyrrolidone used porogen were studied.

Progress of Research on Modification in Polybutylene Terephthalate

This paper introduces the characteristics and application of polybutylene terephthalate, and then focus on the researches to remove its disadvantages. On this basis, we discuss the influence of different modification methods on the properties of polybutylene terephthalate, and the prospect of the modification has been described as well.

Enhanced Anticorrosion Properties of SnO2 Coatings in Simulated PEMFC Environments by Hydrothermal Treatment

SnO2 coatings were supplied on the surface of 304 stainless steel (304SS) by a sol-gel process followed by hydrothermal treatments at different reaction temperature and time, respectively. The effects of hydrothermal temperature and time in pure water on the anticorrosion performances of the SnO2 films in simulated proton exchange membrane fuel cells (PEMFC) environments were investigated by potentiodynamic polarization curves, open circuit potential-time curves and electrochemical impedance spectroscopy (EIS). It was found that the SnO2 coated 304SS via the hydrothermal treatment showed a better corrosion resistance than the sample without hydrothermal treatment and bare 304SS. The SnO2 coated 304SS hydrothermally treated at 160°C for 3h showed the highest corrosion resistance among the samples. The results have been discussed in terms of surface structure of SnO2 film and its anticorrosion performance in simulated PEMFC environments.