High energy ball-milled Ti₂RuFe electrocatalyst for hydrogen evolution in the chlorate industry

The high energy mechanical alloying of a Ti–Ru–Fe powder mixture (atomic ratio 2 : 1: 1) has been performed by extensive ball-milling in a steel crucible. The structural evolution of the resulting materials has been studied by x-ray powder diffraction analysis. The identification of the various phases present in the materials, as well as the crystallite size and strain, has been performed by Rietveld refinement analysis. In the first stage of the material transformation, Ru or Fe atoms dissolved into Ti to yield to the formation ofβ–Ti. Upon further ball-milling, almost all the original constituents of the powder mixture have disappeared and a new simple cubic Ti₂RuFe phase is formed, with a crystallite size as small as 8 nm. The electrochemical properties of these materials have been tested in a typical chlorate electrolyte by cold-pressing the powders into disk electrodes. At 20 h of ball-milling, where the phase concentration of Ti₂RuFe reaches 96%, a reduction of the activation overpotential at 250 mA cm⁻²of nearly 250 mV is observed when compared to that of a pure iron electrode.