Antimony Aqueous electrolysis

A.sahi Chemical EHD Processes. In the late 1960s, Asahi Chemical Industries in Japan developed an alternative electrolyte system for the electroreductive coupling of acrylonitrile. The catholyte in the Asahi divided cell process consisted of an emulsion of acrylonitrile and electrolysis products in a 10% aqueous solution of tetraethyl ammonium sulfate. The concentration of acrylonitrile in the aqueous phase for the original Monsanto process was 15—20 wt %, but the Asahi process uses only about 2 wt %. Asahi claims simpler separation and purification of the adiponitrile from the catholyte. A cation-exchange membrane is employed with dilute sulfuric acid in the anode compartment. The cathode is lead containing 6% antimony, and the anode is the same alloy but also contains 0.7% silver (45). The current efficiency is of 88—89%, with an adiponitrile selectivity of 91%. This process, started by Asahi in 1971, at Nobeoka City, Japan, is also operated by the RhcJ)ne Poulenc subsidiary, Rhodia, in Bra2il under Hcense from Asahi. 

Organoboron complexes of the MR BR3 andMBR4 MAlR4 types merit attention from the safety standpoint. Numerous metal alkyls can be prepared by electrolysis of these compounds (Table 11). It is recommended that the dimethyl ether of diethylene glycol should be used as solvent. A small amount of water is added to increase the electrical conductivity of the solution [110]. Electrolysis of tetraalkylboron complexes in aqueous solution with a soluble anode has also been described [58]. In this last case alkyl derivatives of mercury, bismuth, and lead are obtained. Tin and antimony anodes become passivated, and the yields of the respective organometallic compounds are small. 

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