Карактеризација на оксидниот слој создаден врз бакарот при корозија во синтетичка морска вода

Вршени се електрохемиски испитувања на оксидните филмови создадени со анодна поларизација на бакарот во синтетичка морска вода при потенцијал од -400 до -200mV (3KE) и температури од 5, 10, 15 и 20 степени Целзиус во времетраење од 3 - 10 минути

Parametri elektrodne reakcija kod korozije bakra i mesinga u sintetickoj morskoj vodi

Бакар и његове легуре како конструкциски материјали налазе врло широку примену у морским условима. Њихова потрошња процењује се на око сто хиљада тона годишње са тенденцијом даљег пораста..

Sophisticated electrocatalysts for economical production of hydrogen, Part B: Elekctrochemical characterization

Electrochemical characterization of composite hypo-hyper d - electrocatalysts for hydrogen evolution reaction (HER) was performed using cyclic voltammetry and steady - state galvanostatic method. Cyclic voltammograms are without any pronounced peaks corresponding to some surface processes, typically for porous electrodes

Sophisticated electrocatalysts for economical production of hydrogen Part A: Structural characterrization

An original procedure was applied in order to prepare composite electrocatalysts for hydrogen evolution reaction HER, containing Ni, Co and CoNi as a hyper d – electronic phase and TiO2 as a hypo-phase deposited on conductive carbon substrate Vulcan XC-72. The catalyst’s support (TiO2 and carbon) was thermally treated on 250 and 480°C in the atmosphere of H2 and N2. XRD and SEM methods were employed in order to elucidate the influence of temperature on the structural characteristics of catalysts

Modifications for the improvement of catalyst materials for hydrogen evolution

The structural and electrocatalytic characteristics of composite materials based on non-precious metals were studied. Precursors of metallic phase (Ni, Co or CoNi) and oxide phase (TiO2) were grafted on a carbon substrate (Vulcan XC-72) by the sol-gel procedure and thermally treated at 250 ºC. Ni and CoNi crystals of 10–20 nm were produced, in contrast the Co and TiO2 were amorphous. The dissimilar electronic character of the components gives rise to a significant electrocatalytic activity for the hydrogen evolution reaction (HER), even in the basic series of prepared materials. Further improvement of the catalysts was achieved by modification of all three components. Hence, Mo was added into the metallic phase, TiO2 was converted into the crystalline form and multiwall carbon nanotubes (MWCNTs) were used instead of carbon particles. The improvement, expressed in terms of the lowering the hydrogen evolution overpotential at 60 mA cm–2, was the most pronounced in the Ni-based systems grafted on MWCNTs (120 mV lower HER overpotential) compared to 60 mV in case of Ni-based systems grafted on crystalline TiO2 (TiO2 prepared at 450 ºC) and of Ni-based systems containing 25 at.% Mo. Nevertheless, even with the realized enhancement, of all the fested materials, the Co-based systems remained superior HER catalysts

Carbon nanotubes as support for Co/TiO2 electrocatalysts for hydrogen evolution

The aim of this work was to apply multiwalled carbon nanotubes (MWCNTs) as a catalyst support in composite Co/TiO2/C electrocatalysts for hydrogen evolution. In order to elucidate the effect of MWCNTs, corresponding catalysts deposited on traditional carbon material Vulcan XC-72 were prepared as well