Catalytic oxidation of phosphite and hypophosphite to phosphate on Pd/activated carbon powder

A non-electrolytic metal-coating technique has been for the oxidation of phosphite to phosphate at 308C. The widely used for the surface deposition of nickel, copper, experiments showed that Pd/activated carbon powder was gold or silver etc. onto base materials [1,2]. The metal the most effective reagent for oxidation among the metals electroplating solution contains such reducing agents as investigated. The reaction was very fast and complete after phosphite (1.2 M) and hypophosphite (0.8 M) in addition 5 min when 1.0 g of 10 % Pd/activated carbon powder was to the metal ion of interest. The reducing ability of metal added to solution (1) (Fig. 1). The oxidation of phosphite electroplating solutions, however, decreases after repeated to phosphate proceeded with a conversion rate of about uses, and finally the electroplating solution becomes 10 % for 1 h when 0.1 g of 5 % Pd/alumina powder was unusable. As much as two million tons of electroplating used. It is assumed that the oxidation is accelerated by the wastes have gone mainly to the Pacific Ocean in Japan. On activated carbon powder because of its adsorptive and the other hand, the limit concentration of total phosphate in porous properties. The conversion rate, however, was 50% wastewater is restricted to 16 mg / l according to the in 1 h with 0.1 g of 10 % Pt /activated carbon powder Japanese Environmental Protection Law. A recovery and instead of pure palladium powder. The oxidation of recycling technique of phosphorus from the wastewaters is hypophosphite to phosphite and phosphate was carried out needed to protect the environment. Recently, Pd/activated using solution (2) (Fig. 2). The conversion of hypo