Supported metals inorganic electrolyte effect

The presence of other materials in the impregnating solution can have a marked effect on the location of the metal within the support particle. These additives have been conveniently divided into three classes. Class 1 additives consist of simple inorganic electrolytes which influence the electrostatic interactions at the solution-support interface. Simple salts such as sodium nitrate, sodium chloride, or calcium chloride do not adsorb strongly enough on alumina to compete with platinum salts for adsorption. Fig. 13.9a 0 shows the concentration profile of platinum on an alumina particle when the impregnation of chloroplatinic acid was done in the absence of any additives. This a somewhat diffused egg shell profile. Fig. 13.9b shows the adsorption profile for the catalyst prepared by impregnation in the presence of an amount of sodium nitrate equimolar to the chloroplatinic acid. Here the amount of platinum adsorbed decreases while the adsorption profile approaches a uniform distribution. It is... 

Supporting electrolyte is the mixture of quaternary ammonium salts and inorganic salt. Quaternary ammonium salts such as ethyltributy-lammoniumsalt are effective not only for increasing the selectivity of adiponitrile generation but also for protection of cathode from corrosion. Inorganic salts such as potassium phosphate and alkali metal borate increases conductivity of electrolyte and prevent corrosion of the anode. 

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