Ni-Decorated Multi-Walled Carbon Nanotubes for Electro-Oxidation of Tri(ammonium) Phosphate as New Hydrogen Source Material

Hydrogen is considered the lifesaver against the highly expected depletion of the fossil fuels. Among the various hydrogen production processes, electro-oxidation of hydrogen-rich compounds (e. g. alcohols) is a promising technology due to simplicity and low cost. The cheap non-precious materials can be exploited for hydrogen generation from alcohols electrolysis with small biases. However, the alcohols are either toxic and/or relatively expensive. Recently, hydrogen could be extracted from tri(ammonium) phosphate using Ni/C hetero-catalytic reaction.([1,2]) In the present study, electro-oxidation of tri(ammonium) phosphate using Ni-decorated carbon nanotubes is investigated. The utilized catalyst has been prepared by a simple one-pot synthesis procedure; calcination of well mixed nickel acetate/carbon nanotubes composite under inert atmosphere at 850 degrees C. The results indicated that the prepared Ni-decorated carbon nanotubes composite is an effective electro-catalyst for tri(ammonium) phosphate oxidation when the nickel content is optimized; 1 wt% metal is the best composition. Moreover, chronoamperometry analysis results indicated that the electro-oxidation reactions is independent on the nickel (oxy)hydroxide active layer, this creates a distinct advantage over alcohols. Workability of the inactive electrode is attributed to the reactivity of both of Ni(OH)(2) and Ni(OOH) species toward tri(ammonium) phosphate electro-oxidation process.