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.
- Green hydrogen: A cage structured material transforms into a performant catalystClathrates are characterised by a complex cage structure that provides space for guest ions too. Now, for the first time, a team has investigated the suitability of clathrates as catalysts for electrolytic hydrogen production with impressive results: the clathrate sample was even more efficient and robust than currently used nickel-based catalysts. They also found a reason for this enhanced performance. Measurements at BESSY II showed that the clathrates undergo structural changes during the catalytic reaction: the three-dimensional cage structure decays into ultra-thin nanosheets that allow maximum contact with active catalytic centres. The study has been published in the journal ‘Angewandte Chemie’.
- Catalysis research with the X-ray microscope at BESSY IIContrary to what we learned at school, some catalysts do change during the reaction: for example, certain electrocatalysts can change their structure and composition during the reaction when an electric field is applied. The X-ray microscope TXM at BESSY II in Berlin is a unique tool for studying such changes in detail. The results help to develop innovative catalysts for a wide range of applications. One example was recently published in Nature Materials. It involved the synthesis of ammonia from waste nitrates.
- Samira Aden joins ETIP PV - The European Technology & Innovation Platform for Photovoltaics ESG Working GroupSamira Jama Aden, Architect Design Research, has joined the ETIP PV - The European Technology & Innovation Platform for Photovoltaics working group “Environmental, Social and Governance (ESG)”.