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Electrodes modified using aggregated cobalt-porphyrin/polymer ligand systems were prepared and electrocatalytic activity for oxygen (O2) reduction was investigated physicochemically.The maximum value of water yield due to O2 four-electron reduction was 56 %.The apparent number of electrons involved in Oa reduction was 2.7 to 3 1.Two reactions due to O2 two-and four-electron reduction occurred on modified electrodes. Modification (adsorption) stability of the electrocatalyst system was over a few hours under hydrodynamic conditions.

The effects of the addition to organic acid baths for displacement solder plating of surfactants used as leveling agents and oxidation inhibitors used as bath stabilizers were investigated.The most effective surfactants were found to be isolated systems of Triton X-100 and laurylpyridinium chloride for the hydrophile-lipophile balance of the surfactants and a mixture of laurylamine and Triton X-100 for a decrease in foaming.o-Aminophenol and o-phenylenediamine, which are conjugated-system compounds of 1,2-substituted benzenes and have moderate reducing power, showed good properties as oxidation inhibitors.

The effect of additives (i. e. complexing agents) to organic acid baths in obtaining solder plating films at 0.8 to 0.9 of Sn / (Sn + Pb ) -molar fraction {0.6 to 0.9 of Sn / (Sn + Pb ) -weight fraction } by displacement plating was investigated by physicochemical methods.An effective plating film was obtained from a basic bath composed of metal salts of Sn and Pb, an organic acid, a first complexing agent (thiourea, abbreviated as TU) and a surface active agent (laurylpyridinium chloride), and the molar fraction of Sn / (Sn + Pb) was 0.50 {the weight fraction of Sn / (Sn + Pb) was 0.36}. It was found that the effective first complexing agent in the compounds containing sulf ar had a C = S group such as TU and its derivatives.The formation of Sn whiskers on the plating film was depressed by adding a second complexing agent (glycine) to the bath. The working efficiency (deposition rate and lifetime) of baths with glycine was similar or superior to those without glycine.