Carbon-supported Pt catalysts in nano-size for proton exchange membrane fuel cell (PEMFC) were synthesized by electroless deposition method with and without using ethylene glycol (EG) and NaBH4 as reductant. Scanning electron microscopy (SEM), energy dispersive x-ray spectroscopy (EDS), and transmission electron microscopy (TEM) methods were used to determine the content, size and the distribution of Pt particles on carbon Vulcan XC-72. The cyclic voltammetry (CV) measurements were used to evaluate the activity and durability of catalyst. A comparison of physical and electrochemical characterizations was carried out on three types of catalysts: Pt catalyst of 20 wt% on Vulcan XC-72 prepared by electroless deposition method with and without EG and commercial catalyst purchased from Fuel Cell Earth LLC (USA). The results showed that with the presence of EG, the size of synthesized Pt particles was around 2–3 nm, in comparison with 4–16 nm in the case without EG and 3–4 nm of commercial catalyst. The CV results expressed that catalysts prepared with EG have the highest activity and durability.

In this report, vulcan XC-72 supported PtNi alloy catalyst nanoparticles were synthesized by electroless deposition method using NaBH4 as a reduction agent. The properties of the synthesized Pt-Ni/C catalysts were investigated and evaluated. Transmission electron microscopy (TEM) results showed that PtNi alloy catalysts dispersed well on the carbon supports and their particle size was in the range of 4–8 nm. X-ray diffraction (XRD) analysis confirmed that the crystal lattice of Pt and PtNi alloy is face centered cubic. In the presence of Ni atom, an XRD pattern showed that structure of PtNi alloy crystal was contracted, which affected the catalyst’s properties. The activity of the catalyst was estimated by electrochemical methods including cyclic voltammetry (CV) and linear sweep voltammetry (LSV). The electrochemical results indicated that the activity of PtNi/C alloy catalysts toward oxygen reduction reaction on cathode of PEMFC was higher in comparison with Pt/C catalysts.

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Normally in proton exchange membrane water electrolysis (PEMWE), the anode has the largest overpotential at typical operating current densities. By development of the electrocatalytic material used for the oxygen evolving electrode, great improvements in efficiency can be performed. In electrochemistry, rare metallic oxides RuO 2 and IrO 2 exhibit the best catalytic properties for the oxygen evolution reaction (OER) in acid electrolytes compared to other noble metals. RuO 2 is the most active catalyst and IrO 2 is the most stable catalyst. An oxide containing both elements is therefore expected to be a good catalyst for the OER. In this study Ir x Ru 1−x O 2 nanosized powder electrocatalysts for oxygen evolution reaction is synthesized by hydrolysis method. Cyclic voltammetry, anodic polarization and galvanostatic measurements were conducted in solution of 0.5 M H 2 SO 4 to investigate electrocatalytic behavior and stability of the electrocatalyst. The mechanisms of the thermal decomposition process of RuCl 3 .nH 2 O and IrCl 3 . mH 2 O precursors to form oxide powders were studied by means of thermal gravity analysis (TGA). X-ray diffraction (XRD) and scanning electron microscopy (SEM) were used analysis for determination of the crystallographic structure, morphology and catalysts particle size. Based on the given results, the Ir x Ru 1−x O 2 (x = 0.5; 0.7) compounds were found to be more active than pure IrO 2 and more stable than pure RuO 2 .

Hydroxyapatite (HAp) and octacalcium phosphate (OCP) layers were formed on Mg- 4mass% Y- 3mass% rare earth (WE43) alloy by a chemical solution deposition method at various pH values of pH 5.5, 6.2, 7.5, and 8.6. Adhesion strength of HAp and OCP layers was evaluated before and after immersing in a medium for 14 days by a pull-off test. The corrosion resistance of these coatings was measured by polarization tests performed in a simulated body fluid (SBF). XRD analysis demonstrated that HAp coating layers were formed at pH 7.5 and 8.6, while OCP coating layers were formed at pH 5.5 and 6.2. Adhesion test results showed that the as-coated pH7.5-HAp layer had the highest adhesion strength of 8.6 MPa, which was attributed to the very dense structure of the coating layer. The as-coated pH8.6-HAp layer showed the adhesion strength of 6.5 MPa. The adhesion strength of the as-coated pH5.5- and pH6.2-OCP layers was 3.9 and 7.1 MPa, respectively, that was governed by the thick and fragile property of the layers. After immersing in the medium for 14 days, the adhesion strength of pH7.5- and pH8.6-specimens decreased to 5.8 and 5.6 MPa, respectively. The pitting corrosion and formation of Mg(OH)2 under the HAp layers were responsible for the decrease of adhesion strength. The polarization tests in SBF at 37 °C showed that the corrosion current density decreased with the HAp and OCP coatings, indicating the improvement of the corrosion resistance of WE43 alloy. The HAp coatings improved the corrosion resistance more efficiently than the OCP coatings.