Tungsten incorporation in nickel doped carbon nanofibers as efficient electrocatalyst for ethanol oxidation

Abstract To find proper non-expensive electrocatalyst materials for ethanol oxidation is a big challenge. Transition metals catalysts are considered as the ideal solution for the electro-oxidation of ethanol. Nickel demonstrates high electrocatalytic activity that makes it the predominant candidate for ethanol electro-oxidation. In this study, the electrocatalytic activity of nickel was improved by the synergetic effect of a co-catalyst (Tungsten based nanomaterial) and a proper support (carbon nanofibers). Due to its high adsorption capacity, a nanomaterial of carbonaceous fibers has been used as support for Ni -based electrocatalysts. Different contents of tungsten incorporated in Ni-doped carbon nanofibers (Ni/C) were prepared and the effect of different parameters such as morphology, W content, calcination temperature, ethanol concentration and reaction temperature on the electro-oxidation performance of ethanol have been studied. At 2.0 M ethanol concentration and 25 wt% tungsten content, the electro-oxidation current density of nanoparticles and nanofibers morphologies were 28.23 and 99 mA.cm−2, respectively. The nanofibers calcinated at 1000 °C shows the highest electrocatalytic activity compared to the samples calcinated at 700 and 850 °C. The sample containing 10 wt% tungsten and calcinated at 1000 °C gives a current density of 2.5 times higher than of the sample prepared at 850 °C. The sample of 25 wt% tungsten incorporated in Ni-doped carbon nanofibers shows the best performance towards electro-oxidation of ethanol in basic medium where a current density of 99.3 ± 0.02 mA.cm−2 was obtained. This work will open the window towards a new non-expensive electrocatalyst in the ethanol electro-oxidation process.