Abstract of the talk// Fluorinated compounds play an immense role in a modern life and, therefore, understanding efficient synthetic pathways is of great importance. On industrial scale the electrochemical fluorination according the Simons’ process [1] is applied, but its mechanism is not fully understood. It is believed to proceed in two stages; I.) formation of a NixFy film on a nickel anode immersed in an anhydrous hydrogen fluoride (HF) under applied external potential and II.) fluorination of a substrate mediated by a higher valent nickel species formed on an anode.

To elucidate this process Beate and her team set up computations to first gain an atomistic understanding of the catalytic, amorphous NixFy film, and second to investigate model reactions on this film. In a first step they investigate with different DFT functionals including ab initio MD calculations the behavior of HF on the Ni(111) surface [2,3] under applied electrochemical potential. At the electrolyte–electrode interfaces modeled as an HF layer on Ni(111) the HF splitting was found to be exothermic even at low cell potentials by forming charged electrode with the anodic and cathodic adsorption of F− and H+ respectively.

In the second step the scientists considered the NixFy film with different surface models based on NiF2. By applying a voltage higher then 3.5 V, higher valent nickel centers are stabilizeed [4-7]. In the third step the actual fluorination of a substrate is investigated in order to elucidate the underlying mechanism of fluorination. Building on the second part surfaces with a formally higher valent Ni4+ centres were chosen as models. The fluorination of CO, CH4 [8] and C2H4 molecules was investigated by means of periodic DFT. After studying the adsorption on the aforementioned surfaces, HF molecules are added to the system to model the anhydrous HF. Especially for C2H4 as a substrate various products can be found, ranging from partially to fully fluorinated ethene to different ethane derivatives. The reaction pathways were subsequently studied with CINEB to gain insight in kinetic properties.