Raney type surfaces prepared by high energy ball milling: application to the synthesis of electrocatalysts for the sodium chlorate industry

摘要

SThe specific surface area of nanocrystalline Ti_2RuFeO_2 alloy prepared by mehcanical alloying is low, typically of the order of 1 m~2 g~(-1). When used as a cathode material for the hydrogen evolution in typical chlorate electrolysis conditions, this alloy leads to a 250-300 mV reduvtion of the cathodic overpotential compared to that of the steel cathodes commonly used in the industry. The apparent activity of this material can be further increased by modifying its specific surface area. The strategy consists of mixing the nanocrystalline alloy with a leachable lement (Al) that is selectively dissolved in a subseuqnt step. SInce the alloy is a multicomponent and multiphase metastable compound, the mixing step ought to be performed in such a way not to modify the structure of th material. Mechanical alloying has been used for that purpose. A ten-fold increase of the surface area following has been used for that purpose. A tne-fold increase of the s urface area following leaching of Al was achieved. Following optimization of the electrode fabrication parameters, a further decrase of 80-100 mV decrease of the cathodic overpotential was observed.