Search

Porous carbon‐based electrodes are frequently applied in electrochemical energy technologies, for instance in fuel cells and redox flow batteries. In previous work, we observed that the final structure of a fuel cell electrode is dominated by both the morphology of the support material and its processing into a 3D porous structure. Herein, the impact of catalyst support morphology on the performance of polymer electrolyte membrane fuel cells was studied comparing carbon‐supported platinum catalysts only differing in the shape of the carbon support material with otherwise similar features. Carbon‐supported Pt catalysts were obtained by carbonization of polyaniline (PANI) in long fibrous, short fibrous, and granular shape. The chemical identity of the PANI precursors was demonstrated by FTIR spectroscopy and elemental analysis (EA). The final carbon‐supported platinum catalysts were characterized by EA, Raman spectroscopy, XRD, and TEM exhibiting similar degree of carbonization, nanoparticle size, and nanoparticle dispersion. The effect of support morphology and the resulting differences in the 3D structure of the porous electrode were investigated by focused ion beam‐scanning electron microscopy slice and view technique and correlated to their fuel cell performance. [ABSTRACT FROM AUTHOR]

BST-ZnO-B2O3-composite thick films have been investigated regarding their suitability as low-temperature sintered tunable microwave dielectrics. The investigations showed that already a small amount of ZnO-B2O3 additive can remarkably reduce the sintering temperature down to 900°C. Microstructural investigations of the thick films revealed the formation of an amorphous intergranular phase and a clustering of particles for high additive amounts. The microwave characterization showed a reduction in relative permittivity, dielectric loss, and tunability of the thick films with increasing additive content. These results demonstrate the potential to tailor the material abilities by varying the additive content. [ABSTRACT FROM AUTHOR]