Key role of nickel ions in the Simons process discovered
Ansammlungen von Nickel-Ionen bilden einen dunklen Film auf einer Anode. © BAM
Researchers at the Federal Institute for Materials Research and Testing (BAM) and Freie Universität Berlin have discovered the exact mechanism of the Simons process for the first time. The interdisciplinary research team used the BESSY II light source at the Helmholtz Zentrum Berlin for this study.
The Simons process is of great importance for the production of fluoroorganic compounds and is used in the pharmaceutical, agrochemical, plastics production and electronics industries, among others. The process is named after its inventor, the American chemist Joseph H. Simons, and utilises an electrochemical process to synthesise fluoroorganic compounds. By passing a current through an electrolyte solution containing hydrogen fluoride at an anode and a cathode, fluorine-containing ions are formed which react with other ions or molecules in the solution to form the desired fluorine-containing compounds.
Although this process has been used for over 70 years, the exact mechanism of the Simons process has so far remained a mystery. All that was known was that a black film forms on the nickel anode during the electrolysis process. In order to be able to analyse this film more precisely, the interdisciplinary research team used the synchrotron source BESSY II at the Helmholtz-Zentrum Berlin for the first time. With the help of a specially developed measuring cell, it was possible to carry out in-situ measurements on the anode, which even allowed individual atoms to be observed during electrofluorination. The investigations revealed that centres of highly valent nickel ions are formed in the black layer during the Simons process, which are crucial for the success of electrofluorination.
This discovery makes it possible to specifically improve the Simons process and make it more efficient, which is of great importance for the chemical industry.
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