Chemists unravel the secret of electron transfer under pressure

Chemists unravel the secret of electron transfer under pressure

The study of fundamental chemical processes occupies an important place in science. In their latest study, researchers from the Friedrich-Alexander University Erlangen-Nuremberg and the University of Munich examined the mechanisms of electron transfer in chemical reactions in detail. These results were recently published in the journal Nature Chemistry and show that redox reactions have far-reaching applications in nature and technology.

Redox reactions are essential processes that play a central role in both cellular respiration and photosynthesis. For example, glucose is oxidized to carbon dioxide during cellular respiration, while oxygen is reduced to water. These processes are not only biologically important, but also industrially relevant, as they are involved in batteries and fuel cells, which generate electrical energy from chemical energy. Electrophysiologically, redox reactions can also be forced by external voltage, for example in electrolysis to produce chlorine and hydrogen .

Proton-coupled electron transfer

A new focus of research is based on proton-coupled electron transfer (PCET). This method allows redox reactions to occur without changing the overall charge. Scientists fundamentally distinguish between two mechanisms of PCET: concerted transfer, in which electrons and protons are transferred simultaneously, and stepwise transfer, in which these steps occur separately. However, until now there has been no direct method to differentiate between these two mechanisms.

To study light reactions, the researchers analyzed the influence of high pressure on light-induced reactions of a special photosensitive molecule in solution. It was found that high pressure, up to 1,200 times atmospheric pressure, significantly influenced the reaction rate. Constant velocities suggested concerted responses, while changing velocities suggested stepwise responses .

Impact on future technologies

The ability to control a reaction from a gradual to a concerted mechanism by increasing pressure opens new perspectives for research. These findings are not only important for the fundamental understanding of electron and proton movements, but could also have implications for new technologies for converting and storing chemical energy. This is particularly relevant for applications in solar fuel generation and hydrogen production.

The mechanisms of redox reactions are therefore a key to the development of new energy-efficient technologies. In a world increasingly reliant on sustainable energy solutions, researchers are challenged to further decipher and apply these complex chemical processes.