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The PtRu/C electrocatalyst with high loading (PtRu of 60 wt%) was prepared by synergetic effect of ultrasonic radiation and mechanical stirring. Physicochemical characterizations show that the size of PtRu particles of as-prepared PtRu/C catalyst is only several nanometers (2–4 nm), and the PtRu nanoparticles were homogeneously dispersed on carbon surface. Electrochemistry and single passive direct methanol fuel cell (DMFC) tests indicate that the as-prepared PtRu/C electrocatalyst possessed larger electrochemical active surface (EAS) area and enhanced electrocatalytic activity for methanol oxidation reaction (MOR). The enhancement could be attributed to the synergetic effect of ultrasound radiation and mechanical stirring, which can avoid excess concentration of partial solution and provide a uniform environment for the nucleation and growth of metal particles simultaneously hindering the agglomeration of PtRu particles on carbon surface. Keywords: Ultrasonic radiation, Mechanical stirring, Synergetic effect, PtRu/C, Passive direct methanol fuel cell (DMFC)

The hybrid material based on WO3 and Vulcan XC-72R carbon has been used as the support of Pd nanocatalysts. The resultant Pd–WO3/C catalysts in a large range of WO3 content exhibit excellent catalytic activity and stability for formic acid electrooxidation. The great improvement in the catalytic performance is attributed to the uniform dispersion of Pd with less particle sizes on the WO3/C support and the hydrogen spillover effect which greatly accelerates the dehydrogenation of HCOOH on Pd. Keywords: Formic acid, Electrooxidation, Pd–WO3/C, Spillover effect

A novel colloid method using (WO3)n·xH2O as colloidal source was developed to prepare Pd/C catalyst for formic acid oxidation. Transmission electron microscopy image shows that the Pd/C nanoparticles have an average size of 3.3 nm and a narrow size distribution. Electrochemical measurements indicate that the Pd/C catalyst exhibits significantly high electrochemical active surface area and high catalytic activity with good stability for formic acid oxidation compared with that prepared by common method. The colloid method is very simple and has great potentials for mass-producing Pd/C and others noble metal catalysts. Keywords: Pd nanoparticle, Colloid method, Formic acid oxidation, Direct formic acid fuel cell

The mechanism of formic acid electrooxidation on iron tetrasulfophthalocyanine (FeTSPc) modified Pt electrode was investigated with electrochemical methods. It was found that a “third-body” effect of FeTSPc on Pt electrode predominates during the electrooxidation process based on unusual electrochemical results. The modification leads formic acid electrooxidation to take place through a desired direct pathway, in which the mechanism is proposed to be the gradual dehydrogenation of formic acid and the reaction of formate with hydroxyl species. Keywords: Formic acid electrooxidation, Electrochemical impedance spectroscopy, Iron tetrasulfophthalocyanine, Polycrystalline Pt electrode

In this work, a new promoter, tetrasulfophthalocyanine (FeTSPc), one kind of environmental friendly material, was found to be very effective in both inhibiting self-poisoning and improving the intrinsic catalysis activity, consequently enhancing the electro-oxidation current during the electro-oxidation of formic acid. The cyclic voltammograms test showed that the formic acid oxidation peak current density has been increased about 10 times compared with that of the Pt electrode without FeTSPc. The electrochemical double potential step chronoamperometry measurements revealed that the apparent activity energy decreases from 20.64 kJ mol−1 to 17.38 kJ mol−1 after Pt electrode promoted by FeTSPc. The promoting effect of FeTSPc may be owed to the specific structure and abundant electrons of FeTSPc resulting in both the steric hindrance of the formation of poisoning species (CO) and intrinsic kinetic enhancement. In the single cell test, the performance of DFAFC increased from 80 mW cm−2 mg−1 (Pt) to 130 mW cm−2 mg−1 after the anode electrode adsorbed FeTSPc. Keywords: Formic acid, Tetrasulfophthalocyanine (FeTSPc), Platinum electrode, Fuel cell, Electro-oxidation

A new electrocatalysis of carbon materials for oxygen reduction reaction (ORR) on Pt/C catalysts was discovered. It was found that there exist two kinds of electroactive sites on these supports of carbon materials, which can effectively electrocatalyze the reduction of peroxide intermediated from oxygen reduction on Pt, as this provides continuous driving force to move the equilibrium toward the production of peroxide from ORR. Keywords: Carbon, Catalyst, Oxygen reduction, Pt, Peroxide

Heteropolyanions of tungstophosphoric acid (PWA) have been successfully hybridized with carbon nanotubes (CNTs) by a severe mechanical milling. The obtained hybrid is electroactive for hydrogen evolution (HE) at potentials as positive as −0.16 V vs. Ag/AgCl in 0.2 M HClO4 aqueous solution and its electrocatalysis is up to the level of Pt/CNTs (20 wt% Pt) for HE, indicating a vigorous alternative to Pt group metals. The HE mechanism of the hybrid was also studied and it was found that the tungsten oxycarbides are the electroactive components for HE. Keywords: PWA, Hydrogen evolution, Pt, Carbon nanotubes, Fuel cells

A novel method was developed to prepare the highly active Pt–Ru–P/C catalyst. The deposition of phosphorus significantly increased electrochemical active surface (EAS) area of catalyst by reduces Pt–Ru particle size. TEM images show that Pt–Ru–P nanoparticles have an uniform size distribution with an average diameter of 2 nm. Cyclic voltammetry (CV), Chronoamperometry (CA), and CO stripping indicate that the presence of non-metal phosphorus as an interstitial species Pt–Ru–P/C catalyst shows high activity for the electro-oxidation of methanol, and exhibit enhanced performance in the oxidation of carbon monoxide compared with Pt–Ru/C catalyst. At 30 °C and pure oxygen was fed to the cathode, the maximum power density of direct methanol fuel cell (DMFC) with Pt–Ru–P/C and Pt–Ru/C catalysts as anode catalysts was 61.5 mW cm−2 and 36.6 mW cm−2, respectively. All experimental results indicate that Pt–Ru–P/C catalyst was the optimum anode catalyst for direct methanol fuel cell. Keywords: Pt–Ru–P/C, Electrocatalyst, Phosphorus, Direct methanol fuel cell (DMFC)

Pd/C catalysts with designed lattice constants were synthesized for the electro-oxidation of formic acid. By changing the solvents in the preparation procedure, it was demonstrated that the different lattice constants of Pd crystallites could be controlled as desired. The varied lattice constants may be attributed to the difference in the interactions between solvents and PdCl2. It was found that the lattice constant had an obvious effect on the electro-catalytic performance of Pd. Keywords: Pd nanoparticle, Lattice constant, Formic acid electro-oxidation