Research

P. Grosse publishes recent results on electrochemical CO₂ reduction in Nature Communications

A team of researchers from the Department of Interfacial Sciences at FHI Berlin has discovered how changes in the structure of copper catalyst particles during electrochemical CO₂ reduction affect their catalytic performance. This should lead to the development of new catalysts that convert the greenhouse gas CO₂ into useful chemicals. Researchers around CRC member Philipp Grosse from project B1 published their work in the journal Nature communications.

The could show how the initial number of catalysts particles, their size and density on the support electrode surface is not a reliable indicator of the actual number of particles present during reaction. More importantly, Philipp Gosse and colleagues show that by optimizing the design of the pre-catalyst structures, the structural evolution under working conditions is influenced and thus also their selectivity. This is also important for the electron microscopists.

Working group plasma electrolysis

The Future German and European Energy System – The Role of Hydrogen and its Production, Transport, and Use

A plasma workshop will take place with a special lecture on electrolysis, focusing on future energy scenarios, by Marcel Fiebrandt from Thyssengas on the 25th of February at 10:00.

The EU's Green Deal and the German Federal Climate Protection Act, adapted in 2021, set the ambitious goal of achieving greenhouse gas neutrality by 2050 and 2045, respectively. The necessary transformation of the world's fourth-largest economy toward climate neutrality requires massive adjustments in all sectors and energy carriers as well as in the energy infrastructure. In the national and European hydrogen strategy, hydrogen in combination with renewable energy sources is assigned a central role for the transformation of the European energy system. This is the case as the properties of hydrogen are able to complement the increasing electrification of the sectors. For example, hydrogen can be stored in large underground caverns, transported in pipelines and used for power generation when renewable energy generation is insufficient, and it provides decarbonization opportunities in applications that cannot or are difficult to decarbonize through direct electrification. As a result, power-to-gas-systems, and especially electrolysers, will play a key role as the interface of electricity and gas infrastructure in the future integrated energy system to couple both energy carriers. In this talk, a brief overview of the future energy system scenarios and their implications on the industrial, mobility, and heating sector will be given. Afterwards, the options of producing hydrogen will be discussed and which requirements they have to fulfil to be integrated effectively and economically in the future energy system. Due to their critical role at the interface of the power and gas grid, special attention is paid to the technical requirements based on the properties and restrictions of the energy grid.

Outreach

CRC 1316 is now on Twitter

The Research Department Plasmas with Complex Interactions (RDPCI) is now on Twitter. If you would like to receive updates on cooperation, progress made in the projects and events, we will now also present these to you via @RDPlasma. The account will cover both information on the CRC 1316 and SFB-TR 87 as well as other projects included in the RDCPI.

Awards

Heraeus Dissertation Award of the Faculty of Physics and Astronomy at RUB for Dr. Katharina Grosse (project B7)

The generation of plasmas in liquids is important for applications such as electrolysis, water purification or medicine, but also opens up a number of very fundamental questions. These plasmas are generated by short voltage pulses in the range of many kilovolts and a few nanoseconds in duration applied to a tungsten tip submerged in water. There is a lively debate around understanding the ignition of these plasmas, as electron multiplication during plasma ignition is postulated to occur either within small nanovoids, small fractures in the water, or as an electron avalanche in the water itself. In both cases, field emission at interfaces or field ionization of water molecules plays a crucial role. Dr. Grosse studied the whole dynamics of these plasmas from ignition to afterglow using time-resolved emission spectroscopy and compared it with modeling of emission and fluid dynamics. It showed that the broad continuum is produced by blackbody radiation, with a temperature of 7000 K, exactly equal to that of boiling tungsten. Electron densities of several 10²⁵ m^-3 can be derived from the strong broadening of the Balmer lines of the hydrogen atoms. Furthermore, a strong self-absorption of light from the region of the plasma channel is observed while light from the running ionization front shows no self-absorption. From this it can be deduced that the plasma runs directly through water and is not formed within nanovoids. Thus, field emission and field ionization dominate. After this first plasma pulse, the high power density leads to the phase transition from water to water vapor and bubble formation within the first microsecond. The high pressure in the range of GPa causes an expansion of the cavitation bubble and the generation of a sound wave propagating in the liquid. This could be directly observed using shadowgraphs. In particular, the speed of sound reaches several 1000 meters per second, indicating the very high pressure at the beginning of the discharge. Based on this measurement, Dr. Grosse has very significantly extended the understanding of these plasmas.