Chemical Insights into the Formation of Colloidal Iridium Nanoparticles from In Situ X-ray Total Scattering: Influence of Precursors and Cations on the Reaction Pathway.

Iridium nanoparticles are important catalysts for several chemical and energy conversion reactions. Studies of iridium nanoparticles have also been a key for the development of kinetic models of nanomaterial formation. However, compared to other metals such as gold or platinum, knowledge on the nature of prenucleation species and structural insights into the resultant nanoparticles are missing, especially for nanoparticles obtained from IrCl precursors investigated here.

The Gas Diffusion Electrode Setup as Straightforward Testing Device for Proton Exchange Membrane Water Electrolyzer Catalysts.

Hydrogen production from renewable resources and its reconversion into electricity are two important pillars toward a more sustainable energy use. The efficiency and viability of these technologies heavily rely on active and stable electrocatalysts. Basic research to develop superior electrocatalysts is commonly performed in conventional electrochemical setups such as a rotating disk electrode (RDE) configuration or H-type electrochemical cells.

Self-supported Pt-CoO networks combining high specific activity with high surface area for oxygen reduction.

Several concepts for platinum-based catalysts for the oxygen reduction reaction (ORR) are presented that exceed the US Department of Energy targets for Pt-related ORR mass activity. Most concepts achieve their high ORR activity by increasing the Pt specific activity at the expense of a lower electrochemically active surface area (ECSA). In the potential region controlled by kinetics, such a lower ECSA is counterbalanced by the high specific activity.

Teaching old precursors new tricks: Fast room temperature synthesis of surfactant-free colloidal platinum nanoparticles.

A fast, simple, instrument-free room temperature synthesis of stable electroactive surfactant-free colloidal Pt nanoparticles in alkaline methanol and methanol-water mixtures is presented. Pair distribution function (PDF) analysis suggests that methoxy substitution of chloride ligands from HPtCl occurs in methanol. X-ray absorption spectroscopy (XAS) studies and UV-vis measurements show that solutions of HPtCl in methanol age and are reduced to Pt(II) species over time.

Catalyst Development for Water/CO₂ Co-electrolysis.

Herein, we discuss recent research activities on the electrochemical water/CO₂ co-electrolysis at the Department of Chemistry and Biochemistry of the University of Bern (Arenz and Broekmann research groups). For the electrochemical conversion of the greenhouse gas CO₂ into products of higher value catalysts for two half-cell reactions need to be developed, catalysts for the reductive conversion of CO₂ (CO₂RR) as well as catalysts for the oxidative splitting of water (OER: Oxygen Evolution Reaction). In research, the catalysts are often investigated independently of each other as they can later easily be combined in a technical electrolysis cell.