Faster Protons for the Energy Industry

RWTH researchers publish article in Nature Materials journal

A group of researchers from the RWTH Chair of Physical Chemistry I, headed by Professor Manfred Martin in collaboration with the University of Tokyo, has succeeded in modeling proton conductivity in an oxide, thus predicting that proton mobility can be increased thanks to percolation. This phenomenon is promising for both basic research and technological applications, for example in electrolyzers or fuel cells. The research team published their results in the article "Nanoscale Percolation in Doped BaZrO3 for High Proton Mobility" in the "Nature Materials” journal.

Hydrogen is regarded as an energy carrier for a sustainable future energy industry because it is produced by a water electrolysis process that uses electricity from renewable sources and it can be stored and converted back into electricity in a fuel cell. Proton-conducting oxides are important components of electrochemical cells in both electrolysis and fuel cell technology. One of the best oxides for proton conductivity is yttrium-doped barium zirconate. However, there was only limited understanding of the connection between complex microscopic proton motion and macroscopic proton conductivity. The team has now succeeded in solving this problem using quantum mechanical calculations and kinetic Monte Carlo simulations. This showed that the geometric arrangement of the yttrium ions in the lattice is key: even short yttrium chains enable fast proton migration along the chains and thus increase proton conductivity. This phenomenon is known as "nanoscale percolation", opens up a promising path to increasing proton conductivity in other oxides as well.

To read the complete article, “Nanoscale Percolation in Doped BaZrO3 for High Proton Mobility”, please go to the nature materials website.