Metal phosides, carbides, nitrides, sulfides and oxides

Since 2016, we are interested in material classes such as metal phosphides, carbides, nitrides, sulphides and oxides. Often declared as ceramic materials, they potentially offer metallic conductivity, higher corrosion resistance and enhanced catalytic activity in comparison to their metal congeners. In the beginning of our journey, the catalytic behaviour of these structure was in the centre of our attention, especially for the hydrogen evolution reaction. Intrigued by their properties, we found new application area as e.g. the oxygen reduction reaction. Besides its metallic character, the increased proportion of covalent bonding expressed in the transition metal-carbon bond enthalpy of e.g. transition metal carbides adds additional stabilization to the system. The metal-carbon bond enthalpy of various carbide materials correlates linearly with the onset of oxidation.

Self-healing materials are an interesting material class as they possess a built-in ability to automatically repair damages. When applying it to electrocatalysis, it seems possible to potentially design catalysts that can withstand harsh conditions such as low pH and high potentials. A self-passivating catalysts based on TiC and Pt heal out irregularity in the Pt-film by the formation of an insoluble oxide species at the solid/liquid interface. The adaptation to the nanoscale and to high-surface-area structures highlight the potential for stable, passivating catalyst systems for various electrocatalytic reactions such as the oxygen reduction reaction.

Further reading:

D. Göhl, H. Rueß, M. Pander, A. R. Zeradjanin, K. J. Mayrhofer, J. M. Schneider, A. Erbe, M. Ledendecker, J. Electrochem. Soc. 2020, 167, 021501.

D. Göhl, H. Rueß, S. Schlicht, A. Vogel, M. Rohwerder, K. J. J. Mayrhofer, J. Bachmann, Y. Román-Leshkov, J. M. Schneider, M. Ledendecker, ChemElectroChem 2020, 7, 2404-2409.