Morphological and structural design through hard-templating of PGM-free electrocatalysts for AEMFC applications.

This study delves into the critical role of customized materials design and synthesis methods in influencing the performance of electrocatalysts for the oxygen reduction reaction (ORR) in anion exchange membrane fuel cells (AEMFCs). It introduces a novel approach to obtain platinum-free (PGM-free) electrocatalysts based on the controlled integration of iron active sites onto the surface of silica nanoparticles (NPs) by using nitrogen-based surface ligands. These NPs are used as hard templates to form tailored nanostructured electrocatalysts with an improved iron dispersion into the carbon matrix.

Nonaromatic naphthocorroles.

New naphthocorrole ligands, display both the cavity size of corroles and the dianionic character of porphyrins. Nonaromatic and yet flaunting deceptively porphyrin-like optical spectra, they are readily accessible a simple protocol.

NiFe-mixed metal porphyrin aerogels as oxygen evolution reaction catalysts in alkaline electrolysers.

Aerogels are a very interesting group of materials owing to their unique physical and chemical properties. In the context of electrocatalysis, the focus has been on their physical properties, and they have been used primarily as catalyst supports so far. In this work, we synthesized porphyrin aerogels containing Ni and NiFe mixed metal materials and studied them as catalysts for the oxygen evolution reaction (OER).

Control of Molecular Catalysts for Oxygen Reduction by Variation of pH and Functional Groups.

In the search for replacement of the platinum-based catalysts for fuel cells, MN molecular catalysts based on abundant transition metals play a crucial role in modeling and investigation of the influence of the environment near the active site in platinum-group metal-free (PGM-free) oxygen reduction reaction (ORR) catalysts. To understand how the ORR activity of molecular catalysts can be controlled by the active site structure through modification by the pH and substituent functional groups, the change of the ORR onset potential and the electron number in a broad pH range was examined for three different metallocorroles. Experiments revealed a switch between two different ORR mechanisms and a change from 2e to 4e pathway in the pH range of 3.

Bifunctional PGM-free metal organic framework-based electrocatalysts for alkaline electrolyzers: trends in the activity with different metal centers.

In order to solely rely on renewable and efficient energy sources, reliable energy storage and production systems are required. Hydrogen is considered an ideal solution as it can be produced electrochemically by water electrolysis and renewably while no pollutants are released when consumed. The most common catalysts in electrolyzers are composed of rare and expensive precious group metals.

Enhancement of the oxygen reduction reaction electrocatalytic activity of metallo-corroles using contracted cobalt(iii) CF-corrole incorporated in a high surface area carbon support.

Molecular oxygen reduction reaction catalysts based on metallo-corrole with the smallest meso-substituent reported to-date, Co(iii)CF-corrole, was synthesized and compared to the well-studied Co(iii)tpfcorrole when adsorbed on a high surface area carbon support. This study shows the improved electrocatalytic performance with the new corrole, attributed to its unique compact structure, which enables surface interactions in favor of lowering the reaction overpotential by 70 mV.

A surprising substituent effect in corroles on the electrochemical activation of oxygen reduction.

Four β-pyrrole-substituted cobalt(iii) corroles were studied as electrocatalysts for the oxygen reduction reaction. The results disclose high dependence of the corrole's performance on its substituents, but once adsorbed on a high surface area carbon, this effect vanishes, resulting in a better catalytic performance than most well-defined molecular electrocatalysts for this reaction.