Application of fuel cell for concentrating caustic soda solution

Introduction of a cation exchange membrane as a separator in an alkaline hydrogen/oxygen fuel cell will result in an increase in catholyte concentration and decrease in anolyte concentration. Porous gas diffusion electrodes were prepared and the performance of the fuel cell with these electrodes has been evaluated. Nafion NX961 was used as the separator. Preliminary experiments were done with different concentrations of sodium hydroxide solution at different temperatures. It is inferred that the fuel cell concentrator is suitable for concentrating alkali solution with a little current outpu

Studies on the influence of metal oxides on the galvanic characteristics of hot-dip zinc coating

In the present work, hot dip zinc coating incorporated with various composite was developed. The effect of ZnO and V2O5 in the galvanizing characteristics of zinc coating was studied with a view to apply the coating for functional application. The pretreatment conditions and bath compositions were fixed based on the available literatures and on the preliminary test results. Different electrochemical techniques were followed to study the corrosion tolerance of the coating. The presence of ZnO had a beneficial influence on the protection span of the coating compared to that of V2O5. The presence of composite reinforced inner layer influenced the alloying reaction between Fe and Zn. The surface topography of the coating was also improved due to the metal oxide incorporation

Anti-corrosion and microstructural properties of Ni–W alloy coatings: effect of 3,4-Dihydroxybenzaldehyde

In the present work impact of 3,4-Dihydroxybenzaldehyde on the microstructural and corrosion behavior of nanocrystalline Ni-W alloy coatings has been elucidated. A systematic investigation on the protection ability of Ni-W alloy coatings in 0.2 M H2SO4 solution was done with the aid of tafel polarization curves and electrochemical impedance spectroscopy (EIS) studies. Corrosion performance of the alloy films obtained in the absence and in the presence of different concentrations of 3,4-Dihydroxybenzaldehyde (0–500 ppm) in the bath was explained in the light of additive concentration. Compared to the blank and other concentrations of additive, 250 ppm of additive containing bath was predicted as the most promising one for the introduced citrate based Ni-W alloy electrodeposition. Low corrosion rate (0.06 mm/year) and high charge transfer resistance (2505.3 Ω cm2), for the electrodeposits, obtained from the bath containing 250 ppm of 3,4-Dihydroxybenzaldehyde supports for its high anticorrosion performance. The marked difference in the corrosion resistance property is ascribed to the formation of fine-grained deposits, smooth surface, and inclusion or adsorption of additive within the deposits in the presence of the additive (250 ppm) in the bath. Further, the adsorption of additive molecules on the metal surface was explored with the help of quantum chemical calculations based on DFT

Effect of phosphorus on controlling and enhancing electrocatalytic performance of Ni P TiO2 MnO2 coatings

Electroless Ni?P coatings have received profound interests in recent years for electrocatalytic Hydrogen Evolution Reaction (HER). Their performance can be significantly enhanced by incorporating metal oxides and tuning the electrochemical and surface characteristics by varying the coating composition. The present work focused on the preparation of Ni?P?TiO2?MnO2 coatings by an electroless method, for catalytic alkaline HER. At first TiO2?MnO2 mixture oxide was prepared and its crystalline phase, elemental, bonding and morphological characteristics were analyzed by XRD, XPS, FT?IR and TEM. The TiO2?MnO2 mixture oxide incorporated Ni?P coatings were developed and their electrocatalytic activity was tuned by varying composition. The electrode with 11.32 at.% phosphorus and 14.42 at.% oxygen on the surface exhibited very high catalytic activity. The optimized Ni?P?TiO2?MnO2 electrode had significantly high activity and accomplished hydrogen evolution at high current densities (250 mA/cm2) with low overpotential (?142 mV) and low Tafel slope. The electrode had high double layer capacitance (1.29 ? 10?3 F). The proposed mechanism of HER on the Ni?P?TiO2?MnO2 electrode composed of Volmer hydrogen adsorption facilitated by Ni metal in the coating and H2 evolution via Heyrovsky reaction